Sunlight, Vitamin D in Pregnancy and Health | Dr Max on Great Birth Rebellion Podcast

In our follow up episode with Melanie Jackson, PhD of the Great Birth Rebellion, we discussed how full spectrum sunlight from UV to NIR offers irreplaceable nutrients for optimal pregnancy and health. 

Show sponsors:

🚨 DAYLIGHT COMPUTER. Blue-light free computer that doesn't wreck your circadian rhythm. Now shipping around the world. Code DRMAX for $25 off.   https://buy.daylightcomputer.com/DRMAX

🥩 WOLKI FARM - Regenerative beef shipped around AUS. Highest quality fully grassfed & pastured pork, beef, lamb & eggs raised with holistic principles. Code DRMAX for 10% off. https://wolkifarm.com.au/DRMAX

🚨 VIVA RAYS. Premium blue light blocking glasses with the most useful 3 in 1 clip on frame sets. Code DRMAX for 15% off. https://vivarays.com/dr-maxgulhane

🚨 GEMBA RED. Highest quality photobiomodulation / redlight therapy devices, shipping within the USA. Code DRMAX for 10% off. https://gembared.com
 
🎤 PRIVATE MEMBERS GROUP on Skool platform - weekly Q&A, my 52-page eBook, PDF resource downloads & more. USD20/month, cancel anytime.  https://www.skool.com/dr-maxs-circadian-reset

Follow MEL 
Great Birth Rebellion Podcast: https://podcasts.apple.com/au/podcast/the-great-birth-rebellion/id1639430316
Instagram: https://www.instagram.com/melaniethemidwife/
Website: https://www.melaniethemidwife.com/
Convergence of Rebellious Midwives Conference: https://www.melaniethemidwife.com/the-convergence-sales-page

Follow DR MAX
Website: https://drmaxgulhane.com/
Private Group: https://www.skool.com/dr-maxs-circadian-reset
Courses: https://drmaxgulhane.com/collections/courses
Twitter: https://twitter.com/MaxGulhaneMD
Instagram: https://www.instagram.com/dr_max_gulhane/
Apple Podcasts:  https://podcasts.apple.com/podcast/id1661751206
Spotify:  https://open.spotify.com/show/6edRmG3IFafTYnwQiJjhwR
Linktree: https://linktr.ee/maxgulhanemd

DISCLAIMER: The content in this podcast is purely for informational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Never disregard professional medical advice or delay in seeking it because of something you have heard on this podcast or YouTube channel. Do not make medication changes without first consulting your treating clinician.

#sunlight #UVlight

🧡 HARDBLOCK Australia's Longest Running Bitcoin-only (₿) Exchange
Use code REGENPOD for AUD 10 of bitcoin post account verification

Transcript

SPEAKER_00 0:41

Welcome to the Great Birth Rebellion Podcast. I'm your host, Dr. Melanie Jackson. I'm a clinical and research mid wife with my PhD, and each episode I cast a critical eye over current maternity care practice by grappling with research and historical knowledge to help you get the best out of your pregnancy, birth, and postpartum day. Welcome to today's episode of the Great Birth Rebellion Podcast. I'm your host, Dr. Melanie Jackson, and this week I'm again joined by Dr. Max Gullhain, who we he spoke to us last week about circadian rhythms, healthy sleep patterns, and how that can impact upon our blood sugar levels, but also our hormone levels in all stages of life. But we did speak specifically about pregnancy. And this is the next piece of the puzzle that we want to speak about today, and that's the impact of light and sunlight on the health and well-being of our bodies and on our physiology. We're also going to talk about the nutritional value of the sun on our skin, on our eyes, and how to use the sun for optimal health. This episode is sponsored by my dear friend and birth prep extraordinaire Poppy Child from Pop That Mama. She's a dualer and hypnobirthing practitioner, and her online hypnobirthing course called The Birth Box has already helped thousands of women get ready for labour. Listen to this recent review of the birth box. The woman says, I'm a first-time mum and I gave birth to my beautiful baby boy yesterday. I've been listening to the birth box on repeat for the past few months, including the day in which I went into labor. And I had the most empowering birth experience, and I can honestly say that listening to the birth box was a huge part of this success. Reframing the pain that you experience during labour can be a purposeful pain instead of a harmful pain, and that really helped me to know that. And just being able to surrender to the wild ride that birth is and let my body take over was the most incredible thing. And this is coming from a pelvic floor physiotherapist based here in Australia. She says, I will recommend it to all my patients. And you know me, I'm so picky about what I will endorse, but I do get behind the work that Poppy is doing. And in the birth box, you'll learn tools to help you manage pain and how to stay steady when labor gets intense. It's all about giving you knowledge, confidence, and a mindset that actually works when the big day comes and for the big days that will follow. Birth Box is rated five stars across the board, and with my code Melanie, you'll get 25% off. So if you're preparing for birth, go to the checkout. You'll be so glad you did. The link is in the show notes. Use the code Melanie to get your 25% off. Welcome back, Max, to the Great Birth Rebellion podcast.

SPEAKER_01 3:47

Thank you, Mel. Looking forward.

SPEAKER_00 3:50

And I will just say before we start, I feel like the last week's episode was a prerequisite. It's kind of pre-listening to what we're going to talk about today. But for those who are not prepared to go back to that episode, can you give us a quick summary of the circadian rhythm? Because it's important as we understand the importance of daily exposure to rhythm-based sunlight, which is the topic that we're going to cover today.

SPEAKER_01 4:16

Yeah, so humans are massively reliant still. We haven't uh become immune or independent from that requirement to get uh to respect the natural 24-hour solar cycle, which is full spectrum sunlight during the day and darkness at night. And what what we discussed last episode was this can conceptual idea of the requirement as being like a yin and yang symbol with a clock face around it. And the the yin and yang symbol implies an an equal and opposite reliance on both parts. It's essential. The key part of the half of the circadian story is nocturnal darkness so that the body can make a robust amount of of melatonin to orchestrate repair of all the body's physiological processes. And what we're going to talk about today is the yang, is the is the light and how important full spectrum sunlight is for human health and for pre health of pregnancy, of the infant, of and and into um the rest of life. There's many ways to to approach this. I think probably the the most useful way is to talk about the spectrum of natural sunlight. So sunlight is emitted. So so this the sun is a star. It's in an equilibrium state, and essentially, not to get into the physics of it, but it it emits energy on this electromagnetic spectrum. That energy hits planet Earth having been filtered by the ozone layer and by by atmospheric gases. And what the ozone layer does is actually filters the most high energy or what we call short wavelength UVC life. So anything under UVB light, which has the power to do a lot of damage, gets filtered out. So when we stand on Earth, we we have this spectrum. It turns out that our visual system is only tuned to see a narrow part of that, this electromagnetic radiation from around 400 to around 700 nanometers. Below that, we have this UV light, and above that we have light in the in the infrared. It turns out that each part of this solar spectrum is providing a unique value to human physiology, and in that way can be thought of as these are all essential light nutrients in their own way. The nuance that we have to make, specifically with respect to ultraviolet light, is that we just have to be smart about exposure habits based on our ancestry, our skin type, and the amount of UV light in the environment because the photons are higher energy and they have the power to move move electrons around and to change and potentially do a little bit of damage. Nevertheless, they're essential and it's essential to have ultraviolet light in our life. And I guess the physiological evidence for that is the vitamin D system and all the physiology that is downstream of having enough vitamin D. And and vitamin D is a is a sunshine hormone. It's more than that. It's what what what we call it's a it is a secosteroid hormone with with pleotropic effects, essentially meaning it's uh it's a hormone that regulates a whole bunch of diverse ranges of of human function, of which skeletal health, calcium phosphate absorption is only the the beginning. We can definitely expand about ultraviolet light and the all the nuances around that. Light in the visible spectrum is mostly important, especially the blue light, for circadian rhythm entrainment. And as we mentioned last episode, the body needs blue, but blue in the context of solar blue, not isolated alien, refined blue from your device, from your LED down lights or from any kind of man-made artificial source. It needs blue from the sun because the the presence of that blue is always balanced by longer wavelength light in the red, in the in the near-infrared. And the the stimulatory effects of of blue light on the body and on the circadian system become balanced by the reparative, restorative effects of the longer wavelength, red and near-infrared light, which is now and has been for the past three decades harnessed in the field of photobiomodulation and low-level light therapy for a bunch of therapeutic and cosmetic uh effects. So that that that's visible light. And then as we go into the near-infrared, it turns out that the dominant or the most amount of light by photon count that hits Earth is in this non-visible near infrared band. So over 50% of light that's hitting Earth is is we can't see, but it's not useless. And it it's far from useless. It's it's actually essential. And it's it's turning out and it's taken research by astrophysicists, you know, optical engineers, people that have no aren't anchored to traditional potential uh, you know, biomedical thought paradigms, to put their hit their intelligence into these areas and finding out that the the body is using near infrared light that we can't see to help run mitochondrial metabolism. So essentially run the state of existence and the the uh everything that enables the steel cells to work is is running on or assisted by near infrared. And if we're inside all day, we're not gonna get we're not gonna get any of those, and we're gonna get obviously excess of of of narrow blue. So each one of those from the ultraviolet at 280 nanometers all the way past 1500 nanometers in the infrared, they're all light nutrients that the body needs. And that all makes up part of the healthful effect of being outside during the day. And when I say outside, I don't mean being beaten down by unf you know, unrestricted daylight all day. I mean being in an ambient environment that contains full spectrum light.

SPEAKER_00 11:08

Okay, so what I'm hearing, because last episode we talked about the importance of seeing daylight on our circadian rhythms. Now we're talking about actual physical exposure to light outside through open windows, through basically uh bathing our bodies somehow in the light, because there's a spectrum of light that we can see, there's elements of light that we can see, but there's also light spectrums that we can't see, but that have positive and beneficial effects on our health. Can you tell us why do humans need sun on their skin or to be outside and bathing in light, not just actually seeing light?

SPEAKER_01 11:52

The effect of light hitting the skin triggers a whole bunch of very, very interesting uh chemical pathways, both biochemical and and biophysical effects. What happens is that when the when the photon actually hits the skin, depending on the wavelength, it gets absorbed. Either gets absorbed or it gets it hits and gets scattered. So in in the shorter wavelength, which means ultraviolet light, the body has developed or adapted a bunch of defenses to benefit from, but also protect against this ultraviolet light. And to colour in what you said earlier, the the crux of the issue here in Australia is that we have a bunch of Northern European explants, people of Northern European descent, who instead of adapting to the massive solar yield and ultraviolet intensity, you know, arrived via ships, that's insufficient time to essentially adapt. So what we can know will realize by the difference in melanin levels in the skin, which is this photo, this pigment that cut that exists in the top layer of our skin, is that there's a difference and there's an appropriateness of exposure depending on ancestry and skin type. So when where we live in Australia, where it gets up to a UV index of 14, which is a measure of ultraviolet B intensity, the people were the darkest shades of melanin, they're the darkest phototypes to the Indigenous Australians. That gives us a clue about what kind of defenses are required. We'll talk about this a bit more, but essentially, if we have lighter skin than the people who adapted to this area over multiple thousands of generations, then we need to essentially be very careful about how we dose that shorter wavelength, that UV light. And we can do that in a number of ways, but the the crux of it is either covering up or simply avoiding being in direct sunlight during peak UV periods and simply get our light needs met earlier in the day. How you can do that is because the amount of ultraviolet light is changing throughout the day based on the sun angle, the zenith angle. So as the sun rises, the amount of s of atmosphere that the light penetrates through is more. So all that UV can't get through. It gets absorbed and attenuated. As the sun rises more and the angle becomes more acute, more overhead, then all that UV can get through. And that's why there's this peak UV period during the during the middle of the day. So where people are at highest risk of of burning, but they're also at at the period where they can generate the most vitamin D. So what happens when ultraviolet light and we'll start here, hits the skin, is that it kicks off a reaction that converts cholesterol, which is sitting in the cell membranes, into vitamin D. It breaks a bond in the chemical structure, and then the vitamin D can form. We as humans have used and repurposed vitamin D to basically run a whole bunch of important programs in the cell. So and the body. So what is happening is that when your body makes vitamin D, it goes through various stages of activation in the liver and the kidneys, and it helps your body to absorb calcium and phosphate from the gut and help retain it at the kidneys. The way we found out about this problem was in in the early 1900s, late 1800s, during the industrial revolutions, in revolution in Europe, where they would they were pumping out all this coal-fired smog in in the cities. And what that did is it acted as a barrier or an absorber to prevent the penetration of ultraviolet light into the cities. So what happened is the children who were not getting any UV light at all developed this bone condition called rickets. And it was vitamin D deficiency because they weren't able to generate enough vitamin D. They weren't ingesting any enough food sources of vitamin D. So they got this bow-legged appearance, which is uh essentially inadequate development of of the long bones because of the vitamin D deficiency. And they there were some very fascinating experiments done, you know, even just observations done, that the farming children in rural areas of I believe it was Poland perhaps, um, they didn't have the same problem. So the question was, what is it about this inner city living was able to, you know, mitigate this effects of of of rickets? And as they progressed, they realized that you if you purified cod liver, cod livers, the fish, then that could essentially prevent this vitamin D deficiency rickets. Again, they didn't know it was vitamin D. Um and then as we went further along in the scientific process, you know, we realized that this was a hormone that you could ingest if it's pre-formed in in certain foods, because it's it's fat soluble, or you can make it yourself. And you can make it, but you need ultraviolet light, and there's these key factors that affect how much vitamin D that can be made. And and environmentally, they're the season, the latitude. Because in northern US, Europe, there's months of the year where there's no there's minimal ability to make any vitamin D and there's seasonal absence of UVB light. And then um there's also factors related to us as individuals. How much skin pigmentation do we do we have? How what are our personal habits? Do we go outside and expose our skin to the sun or not? So, you know, these all these things affect how much vitamin D we make and therefore influence at the basis bone health. As it relates to pregnancy, the pregnant woman has to mobilize and use a massive amount of these products, calcium, phosphate, to essentially ossify a fetal skeleton to make a baby's bones. It's it's a massive demand. There's probably um you know multiple pathways that ensure that that baby gets those factors, um, you know, potentially even at the expense of the mother. But it it highlights how important it is for the mother to get sufficient vitamin D because the baby can't generate its own yet. So it's reliant on maternal intake of vitamin D or maternal sunlight exposure to to make enough so that it can grow grow its own uh skeleton. But it turns it turned out, and this is research more in the past probably 20 years, that the vitamin D was having way more effects than simply just the skeletal system. As it specifically relates to pregnancy, because that that's what we're interested in at the moment, it seems to control inflammation, the inflammatory system, but also neuroinflammation and brain development. So vitamin D is a is a brain-essential nutrient, and without it, you you're not gonna get the proper formation of the baby's brain. But it also influences and it all essentially the vitamin D serum level can be thought of metaphorically as a switch that influences the immune inflammatory state of the body. If you if you're in a state of vitamin D deficiency or insufficiency, then you're potentially activating a bunch of pathways that predispose the body to a pro-inflammatory state. This seems to have relevance for uh neuroinflammation in in the baby and actual epigenetic imprinting for that baby uh going forward. But not only that, it's it's critical in in correct placental function, in in the function of the placental vessels, and therefore deficiency is uh you know a risk factor for uh pre-eclampsia. Other than you know, pre-eclampsia, this it's also associated with failure to progress because vitamin D is also necessary for muscle, the for muscle function, and the myometrium needs needs an adequate vitamin D to essentially provide the contractive force to facilitate birth. So there's there's all these fascinating aspects to to vitamin D. But whenever you hear about vitamin D, whenever you read the literature about vitamin D, I want you to think about ultraviolet light, because ultraviolet D light is how we get 90% of our vitamin D needs met.

SPEAKER_00 20:39

And as you were talking about vitamin D being anti and anti-inflammatory and and how that relates to pre-eclampsia, because there's some inflammatory processes, you know, uh there's inflammatory processes to do with preterm birth, with pre-eclampsia, and yeah, with poor placental function, they all have an inf inflammatory element. As I check the bloods of all of my clients, I can see really, I think I reckon 85% of them are vitamin D deficient. And when I'm talking to everybody about, okay, gotta get your vitamin D levels up. Part of that is appropriate sunlight exposure. And as you already said, the darker your skin is, the more sun exposure you need in order to feel the impact of that because of the high level of melanin. But the the flip side is if you've got fair skin, you could get your vitamin D and sun exposure in faster, particularly if you're in a in a in an environment that has high uh UV index. So what you're saying, so in places where they see a lot of sun, sorry, a lot of rain and overcast, you would do better to live there as a fair-skinned person than um than in Australia, obviously, uh because of the less sun, but actually you need less sun because your skin's fairer. Uh so there's that part of the conversation. How does supplementation fit into this? Because if a woman was to go to her GP or doctor with a vitamin D deficiency, the remedy probably wouldn't be sun exposure. Uh, I'd uh there would be an element where they're like, yeah, go and get your skin into some sun, but not too much sun. Uh they would recommend supplementation. So, and you mentioned actually that vitam there is vitamin D in some foods. So we can consume vitamin D, we can absorb it, or well, we can get it from the sun through various um physio uh like physio physiological. Processes. How do those two go hand in hand? Because can you fix a deficiency with just regular daily sun exposure or is supplementation needed in that moment?

SPEAKER_01 22:56

Okay. Yeah. Great questions. The way, and maybe we need to define what is vitamin D deficiency, because there's actually even discrepancy in the literature here. The unit that we measure when when you get your blood taken from your doctor to measure your vitamin D level, it measures a circulating form of vitamin D called 25 hydroxy vitamin D. This is this is essentially a form a storage form which then gets activated through enzymatic steps in in the tissues where it's needed. But it's it's a good proxy for your vitamin D status. So in Australia, the the lower limit of deficiency here is defined is 50 nanomoles per litre. In the early to 2010s, the US Endocrine Society, in recognition of these massive number of effects and benefits of or associations of vitamin D deficiency with cancer, with autoimmune disease incidents, with infectious diseases susceptibility, with metabolic and cardiovascular disease susceptibility with even all-cause mortality in these observational studies, they revised their recommendation and called 75 nanomoles deficient, anything below 75 nanomoles deficient. Interestingly, if you know I see patients in general practice, the endocrinologists, they treat all their osteoportic patients, you know, they need them above 75. The neurologists, when they treat MS, they want everyone to be over 100. So these other medical specialties are providing hints at understanding the importance of vitamin D, but again, they they they they default to supplementation. I think what we should aim for at a bare minimum is repletion by those criteria from the US Enterprise Society, headed by my Professor Michael Hollock, which states anything under than 75 is is undesirable. And look, they've established that in a number of ways, basically looking at inflection points of uh you know disease incidence, but also biochemically with with um things like the changes in the parathyroid hormone. But the point is you can build up the vitamin D through supplements and through natural exposure. The massive controversy with respect to vitamin D in medicine and science is anchored in the following, and and it is extremely controversial. Because what incurs through through vitamin D supplementation is a purified D3, is not the same as generating vitamin D through the skin. It's not the same. So what we can do to raise the level through supplements can prevent the Frank complications. And you know, anyone under 75, I recommend that they supplement up at least up until that level. But beyond that, it there doesn't seem to be benefit in these interventional trials from supplementation. So a lot of researchers have taken that as, you know, okay, nothing to see here about this whole vitamin D story. But really, we need to take a step back and think about this problem a bit harder. And it turns out that the vitamin D's not the same. When you generate it in the skin, it essentially gets bound to a vitamin D binding protein and provides this really consistent release throughout for the next three, four, five weeks. It's got a longer half-life. When you take it orally, it it binds to the lipoprotein fraction. It's it's less specifically delivered to where it needs to go. What also is happening here is that the serum vitamin D level is actually a proxy for someone's sun-seeking exposure and sun-seeking behavior. So it's almost a way of measuring or understanding how not how much only how much ultraviolet B light they've gotten, but how many healthy circadian signals they've got, how much near infrared light they've had, how much time that they've spent in outside in nature. What it means is that wherever possible, we want to build and generate our vitamin D through natural exposure, through sunlight, keeping in mind everything that we talked about with respect to dosing, which needs to be done depending on skin type and depending on on latitude. To be clear about the number of pregnancy-related complications that can be avoided, can be prevented with uh vitamin D repletion. I'll reference this study. It was a meta-analysis from 2024, the effects of vitamin D in pregnancy on maternal and offspring health, uh, umbrella review of systematic review and meta-analyses. And they obviously went through 16 eligible systematic reviews and meta-analyses, including 250,000 women. And they result the results demonstrated that vitamin D deficiency in pregnancy is associated with an increased risk of preterm birth, small for gestational age, uh, recurrent miscarriage, bacterial vaginosis, and gestational diabetes mellitus. And vitamin D supplementation in pregnancy increases birth weight and reduces the risk of maternal pre-eclampsia miscarriage, vitamin D deficiency, fetal or neonatal mortality, as well as attention deficit, hyperactivity disorder, and autism spectrum disorder in childhood. Conclusion is that we need to be, we need to be avoiding vitamin D deficiency. So how we do that, I think now is the key point. And what I would advise is to, again, supplement if we're under 75 at the same time as getting an appropriate skin type appropriate amount of sunlight to uh generate it in our skin. So the the question is, how much sunlight is enough? And that is a pretty important question when it comes to dosing this. And Michael Holleck, Professor Holleck, who again was was the endocrinologist uh at uh in in Boston and discovered the active form of vitamin D, he did studies and basically found that if you give people whole body exposure with enough UVB light to just about develop some redness, then you you you're potentially generating about 20,000 units of vitamin D. So that is that's a massive amount. If you think one pill contains a thousand units, you you can generate 20 times that by essentially just getting up into the the burning stage, which is obviously not what I we don't advise to go to burning, but what it shows is how efficient the body can be to make this compound in in the skin. So again, and that is the the good form, that's the great uh pathway because it it provides a really slow release uh form of of the of the uh hormone and it helps it keep releasing it uh and getting it to exactly where it needs to go. What we should aim for, if again, we're potentially over the de Franc deficiency threshold and when we're above 75 nanomoles is working on potentially getting 10 minutes, 15 minutes of exposed skin potentially on this on our uh admin, on our whole on our whole body, uh per day without burning. And what time of the solar day we do that is gonna depend on how much skin pigmentation we have. If we're from Somalia originally and we have this Fitzpatrick six skin type, then you can safely go out in UV indexes of 12 and it close to the midday, it's not gonna be a problem. You're not gonna burn. And and those women have an abundant amount of an extremely protective form of melanin, um, U melanin, which is is a 99%, 99.9% efficient at dissipating ultraviolet light and converting it to heat. If we're of northern European, you know, Scottish descent with red hair, and we're living here in northern northern New South Wales, then maybe you you you're only gonna need 15 minutes from 8 a.m. till 8.30 till to you know 8.40. It might be as short as that to get our knees met, and then when UV index climbs, we go inside. So I guess that the key point here is we we're gonna dose our ultraviolet light so that we build up a healthy vitamin D and hope hopefully prevent this raft of of pregnancy complications.

SPEAKER_00 31:15

So what I'm hearing is that the supplementation and sun exposure are two different kinds of vitamin D. Use them together to remedy a deficiency, but then once you get over the deficiency threshold, you can maintain your vitamin D levels with a relatively short amount of exposure at an appropriate time of day for your skin type. And because we can move all over the world now, we can live in a place that's not appropriate for our skin type. So possibly my husband would not get vitamin D deficient if we moved to London, whereas I would be more likely to because I need more sun exposure for my skin type. So, what we do know is that pregnant women are perpetually deficient of vitamin D and we're and everybody's trying to get their vitamin D levels up. I think you're right about the the thresholds. A lot of the blood test thresholds are like this is how much you need to be not dead, and then it's fun like, but it's not the optimal healthy levels. It's just, hey, you're not gonna die with a level of this. So with a lot of things, the the levels for health are actually higher than the the clinical thresholds that are offered in the blood tests, but vitamin D seems to be the same. Are you getting ready to have a baby? And if you are, what are you gonna do about the pain of contractions? There are lots of things you can do. In fact, I'm gonna tell you about them because I've been watching women give birth without pain relief for over 18 years. I'm Dr. Melanie Jackson and I'm a home birth midwife. I had my own babies at home without pain relief, and I've been helping other women do the same for my entire career. If you want the top tips and tricks that I recommend to help women give birth without pain medication, it's all here in the link below in my guide to giving birth without pain relief. You can do it. Give it a go. Why not just prepare?

SPEAKER_01 33:15

Can I can I make a point about another difference, key difference between supplementation versus sunlight derived vitamin D? To get what we call hypervitamo hypervitaminosis D to get excess, you you need quite a heroic dose. You need, you know, probably more than you know 50,000 units uh a day for quite many, many months to get what we call hypercalcemic uh hypervitaminosis D and the serum calcium rises. We you know, the the you you you get a Frank syndrome of of hypercalci uh vitaminosis D. That that takes a massive amount of vitamin D supplementation, which most people don't come anywhere near to. However, interestingly, so um, if we're generating it in our skin, there's there's actually no physiological possibility of becoming toxic in vitamin D. And that's because what the body does is it if if you continue to irradiate uh with more ultraviolet light, then the body just shunts these uh vitamin D into other pathways. So it breaks the the compound down into these related psychosteroid uh compounds that essentially again could pr prevent the body from getting in excess. But obviously, we don't necessarily need to or want to be roasted to a crisp at all, but we we we want to play with uh an appropriate amount to get these needs met to uh you know generate well-being. A related pathway to vitamin D with respect to its stimulus by ultraviolet light is this this peptide uh pro-hormone, it's called pro-opiolomelanocortin. It's a it's a bit of a handful. But the what what women need to know and what ever I think everyone should know is that it's stimulated by ultraviolet B light as well, and it mediates both the pigment response, so making more melanin in the skin, and it also cleaves off an endorphin. So it was just called beta endorphin. So the body rewards you for generating vitamin D by being in ultraviolet light by making some of this this opioid that can be thought of as again the body rewarding you for for giving it what it needs and what what what it wants.

SPEAKER_00 35:32

So basically you're saying when our skin is exposed to sunlight, it activates an endorphin reaction and we feel good. And people do. If you go outside and you're in the sun, universally people go, that's nice. Like that was nice to go outside. That's your endorphins telling you, hey, this is good. So I uh way back a long time ago, I read somewhere that if so that that the impact of sun on your skin, and I could be completely wrong, but it needs to settle in. So we we're in a society that's obsessed with hygiene and daily showering and soaps and products and things on our skin. Is it true that if you like wash and shower daily with soap that you like if for lack of a better explanation, like wash off the vitamin D that would have otherwise soaked into your skin, and that this kind of overuse of products and hygiene products is getting in the way of our body being able to benefit from the sun exposure?

SPEAKER_01 36:42

It's an interesting question, and I think it was originally proposed because non-human mammals like primates, they generate vitamin D in their fur, their exposed fur, and then they lick the fur to essentially get get their vitamin D. What happens in this the human skin is that when when this cholesterol gets turned to vitamin D, it seems to get immediately ejected into this um you know, the interstitial space and into the capillary beds and then it binds. So uh Hollett did some research that suggests that this wasn't significantly affecting uh absorption, whether or not you you know immediately wash off, uh, which is which is is is a good thing.

SPEAKER_00 37:23

Those are the questions I had about vitamin D, because I don't want women to be frightened of exposing their skin to the sun because of the pervasive messages about you know the the dang the potential dangers of extended sun exposure, but we've got to remember that we actually need sun exposure to maintain our health. And during these extenuating times of being pregnant and feeding and caring for our babies, we want to do everything we can to be nutrient abundant instead of deficient.

SPEAKER_01 37:55

Absolutely. There's there's a couple points I'll I'll make. You know, there's some data to suggest that potentially 6,000 units a day is the threshold to ensure enough is being passed through into the breast milk. Um there was a study done by Hollis 2011, I believe, showed that 4,000 units was more than uh completely safe in terms of tolerance during pregnancy and and with no adverse effects. I I think what you generate from natural exposure, you know, 15-20 minutes with as in the way that we've discussed, you're gonna make a lot more than that. Uh uh and you're gonna you probably do the best thing to ensure that there's enough being put into the breast milk. That that's UVB light, and and really maybe the the last thing to say about it is that in medicine we we we make a determinant of risk versus benefit for for basically every intervention, whether it's a drug, whatever we're recommending. And and I really think that light and shortwave length light, UV light falls into that category. The long-term risks of potentially photoaging, solar ostosis, skin cancers, they are modulated by lots of things, oxidative stress, circadian rhythm disruption, particularly with respect to cancer. But uh the point here is that where there's a benefit phase, there's a benefit spectrum that is happening during pregnancy. And we just need to be smart about balancing those risks and benefits so that we're giving us the best chance of having a a healthy birth and and and having a healthy child and and and baby. So um if you don't have any more questions about vitamin D, maybe we could briefly touch on on visible on some of the visible light pathways.

SPEAKER_00 39:35

We could. I also had one and one other question that occurred to me. What are the foods if we wanted to eat vitamin D, what are those foods?

SPEAKER_01 39:43

The the richest sources of uh of vitamin D are going to be found in things like uh sardines, uh you know, some of these cold water fattier fishes. I'm talking about naturally occurring, not fortified, because in many places of the world they're actually fortify foods with with vitamin D. So, you know, that that would probably be my pick. And and I really like sardines and and those fatty fish because they also contain DHA, iodine, zinc, selenium, you know, all these brain essential nutrients that can only be found in abundance in in the marine food web. Um, you know, so eggs, if that if and they've done studies uh comparing the vitamin D content of fully pastured eggs that the hens have been grazing or or foraging on open pasture exposed to sunlight, they have a greater vitamin D level than the hens that are shut up in a confined-fed factory operation, which shouldn't be surprising at all. So if you need another reason to spend an extra$4 on on the fully pastured eggs, you're getting more nutrition in addition to the choline and and and you know the B vitamins you're getting from your eggs, you're also gonna get more vitamin D. So th those would probably be my pick. You know, there's there's other foods that also contain uh vitamin A, so you know, cod liver and and root bobone liver. I'm not gonna comment on that. Uh I think you probably had other guests to to discuss that, the nutritional aspects, only to suggest that they are also a rich source if if some women are choosing to uh to eat them in pregnancy. And obviously, Lily Nichols, I think, is has got some really good.

SPEAKER_00 41:20

Yeah, Lily Nickels is excellent for that. I'm so glad you said that about the chicken eggs, because I'm actually writing a book at the moment called A Guide to a Great Pregnancy. And one of the I just can't get away with it, but I'm away from it. But I'm putting kind of a list of things that I think everyone should do. I mean, regardless of if they're pregnant or not. And one of the things I was suggesting to people is buy four chickens. Like that's on the list of things to do because eggs are so full of nutrition, but actually the the food production line for eggs is so uh devastating in terms of how they treat the chickens and their, you know, how healthy the chickens are versus how healthy the egg is, and the fact that they're yeah, confined and not exposed to sunlight. And you're saying the ones that get to roam free, of course, if they're exposed to more sun, their eggs are gonna have more vitamin D. It's um it's a no-brainer, but that reminds me to just keep that in the book because I keep looking at it, going, you can't tell people to buy chickens, uh, you know, if they want to have a great pregnancy. But um, I feel like I can actually.

SPEAKER_01 42:29

Definitely.

SPEAKER_00 42:30

Um, all right, so you were gonna say if we're finished with the vitamin D conversation, what next did you want to tell us about sun exposure for health?

SPEAKER_01 42:40

So if we're progressing along the spectrum from shorter to longer wavelength light, and we've we've got our UV or we've dosed our UV, what it seems like was the one of the most important uh ancestral and evolutionary environments was the tree, or interestingly, the visual peak of visual human discrimination is actually in the green. The rainforest has some really interesting effect on the natural light spectrum. It actually blocks, prevents the penetration of lots of UV, uh, but it allows for this massive amount of red and and and more near infrared, so in that that non-visible. And this gets to the point that I mentioned in in our first episode, which is that this optics engineer kind of analyzed the human body and and has found that we're designed to harvest near infrared photons and concentrate them into uh into really sensitive areas like the brain and like the uterus, the fetus. And what is happening, the near-infrared light is actually stimulating the production of melatonin, the same melatonin that the pineal gland makes, but but melatonin being made on site in our mitochondria during the day. So it's a way that the body is is is actively mitigating oxidative stress and generating beneficial tissue healing effect throughout throughout the day. So what what I guess I'm I'm saying here is that part of this idea of optimizing our our health with respect to sunlight is dosing our UV as we discussed, but trying to spend as much time simply outside, but potentially undercover, surrounded by greenery and surrounded by bushes. Because the the other thing that was was discovered is that plants use a whole bunch of red and blue light to photosynthesize, and they reflect the near infrared to the environment because they don't want to overheat. They're very, very efficient in that. So this is where we come in, you know, walking through the forest, is we're collecting all this waste energy, which is sunlight being reflected by the leaves and the plants that they don't need for photosynthesis. But we use essentially photometabolism in our mitochondria. This is like a, you know, mind-blowing moment when you realize the healthiest place to be during the day is surrounded by plants in in the shade, in greenery, uh, and that's that's creating all this massively benefit antioxidant effect that so vastly outweighs you know any the dietary antioxidant formulation. It's simply natural antioxidant generated by being in a healthy, full-spectrum daylight.

SPEAKER_00 45:26

So basically, what we really already know, but that science is catching up is that humans need to be outside in nature with nature. So do our animals. Anything that's producing our food needs to be outside to optimize the quality of our bodies' functions and for the of the food system. It really isn't rocket science, Max, but we unfortunately have to have conversations with people in these modern lifestyles to say, hey, you actually just have to go outside for a little bit for the sake of your own health. And all of those needs are accentuated in pregnancy because of the extra work that we're doing. But also, and and in the conversation we had last episode about the and about the circadian rhythm and about habits of going outside and sun exposure. If we are doing these things as parents, if that's how your lifestyle revolves, and that's certainly what's happened in our family, is the kids are all aware that at night time the orange lights come on. And you know, sometimes we've done wild things like done a flight overseas and the lights are intense, and so and I'm putting red light glasses on all the kids and my mum and myself and going, runny, everybody. And but they're learning, okay, this is important for us. This is what we do in our family. So not only are you teaching them, but also you're protecting them. But same thing with the sunlight exposure, if you're doing it, you're immediately going to entrench this culture of being outside and with nature into your children. So this is generational health. You know, we talk about generational wealth, is the things that we do impact the, you know, the wealth of our next generation. But this is generational health.

SPEAKER_01 47:12

Absolutely. And look, it's no different to developing or fostering, promoting healthy eating habits. Just like a family makes a conscious choice to not buy processed foods and and and not bring in McDonald's into the house or chocolates and excess chocolates and all and lollies and soft drinks. We so so can put in place these healthy light habits, which is we don't turn on overhead down lights after dark. That's not something our family does. There are a whole number of little tricks or habits that you can employ to help everyone get these healthy kind of signals. So going straight outside when everyone wakes up is a really good one. The the goal is to everyone go outside, we stand on the grass, we play, we just we're engaged outdoors. And although they don't realize it, they're actually checking a whole bunch of boxes on the circadian requirements. They are moving their body. So we didn't talk about movement, but physical movement is an another zycar to help uh entrain the circadian rhythm. They're getting this bright morning sunlight, we're getting you know light potentially on the body, and uh the the body is is completely permeable to to light. This near-infrared passes all the way through the body, um, eight centimetres, meaning that younger children are potentially more impacted or more influenced by their light environment than adults, and they're more susceptible to or potentially beneficial from from this from these light photons. So getting getting everyone outside, you know, what it can be anything, it depends on on where you live, but you can all walk towards to the local hill, see the sunrise come up if you if everyone's up. Um I I I recommend that, and maybe this is the deeper cuts of the circadian lifestyle, but if for those who are really committed, getting up and and watching the sunrise together is is an extremely powerful way of entraining the circadian clock because it's the brightest amount of the biggest change delta from from darkness to to bright. It's an amazing signal to cut off melatonin production, start uh ramp up healthy cortisol and get the day going. So you can all walk together. I mean, there's so many different ways of doing it. You can you can set up a playground outside facing the east. So all the kids just play and they're and they're getting that east. You can you know put people in it, put them in a little beach cart and you know walk to the local corner where you can see where the sun comes through the trees. There's there's so many ways of doing it, but it would ever however use your imagination, just try and build in healthy light habits into your daily routine in a way that that's gonna work for everyone in the family. And and then become second nature because again, it's it's about sustainable and long-term lifestyle change rather than you know doing this for a week because I'm pregnant.

SPEAKER_00 49:59

And the other thing I've noticed is if you get in the habit of it, you actually feel the impact of not having it when you don't do it, and you think, oh my gosh, I feel why do I feel this? And you think, oh, that's right, something just changed, you know, maybe a change in your routine or something. And you can feel when you don't do it. The other question I wanted to ask is if you're in a privileged position where you where natural light comes into your home and you can see the sunrise from a window in your house, for example, how do you optimize that opportunity? Because I have heard that having the windows closed versus having them open changes the impact again on the benefit of the sunlight. So, for example, I've got these big windows at the back. We intentionally put them at the back because that's where the sun rises. And we thought, wouldn't it be great to watch the sunrise? But if they're closed, there's a different impact to if they're open. Can you talk to us about that? How do we optimize light if we're inside?

SPEAKER_01 50:59

So anytime you filter light with a car window, with windows of your house, uh, with sunglasses, depending on the structure of that surface or that uh window, you are going to change the spectral composition of the light that's that gets transmitted. And therefore you're going to change the photobiological response. Because the body is tuned to the signature of light exposures, which is always anchored or dictated by what is what natural unfiltered sunlight is doing. So anytime you change it, you're going to change the message. So therefore, the goal, wherever possible, is to get unfiltered light into the eyes and obviously on the skin, depending on time of day and UV index. So what is that what does that look like? It looks like opening windows, and because the physics of light ensures that you you don't need a massive amount of opening to get photons through there. So you can even crack the window a little bit on the car. You'll open one louver, open the sliding doors, you that's that's much preferable to uh to to filtering the light. Is filter light better than plain artificial light? Absolutely. Um and you're still getting brightness. So it's a there are shades of optimal here, and obviously just do it, do what you can. To make a maybe a quick revisit to ultraviolet, is that because ultraviolet is short wavelength, it will get readily attenuated by clothing. So it doesn't take a lot to still be outside, but to cover up. And that's kind of what what I what I recommend after we've dosed ourselves appropriately, is to cover up and and preferably what what they found is that the natural fibers, like a linen particularly, uh penet protects against or prevents UV penetrating, but is very permissible to that those near-infrared longer wavelengths that that have all this have such a massive and beneficial health health effect. So the that that needs to be be taken into account. And sunscreens, sunscreens are by definition ultraviolet blocking. So they are going to inhibit the photochemical conversion of 7D hydrocholesterol to vitamin D. The significance of that for vitamin D status is minimized by current recommendations. It's my personal opinion that that is an important factor. So use use that information, with do with that what you will. And potentially also of relevance with respect to exposure and sunlight is the link between the eye and the skin. And what we know and what we discussed last episode is that what is happening through the eye, the light through the eye, affects the systemic endocrine system. One of those endocrine functions is the tanning response. So whatever we want to do when we're when we're outside is to make sure that the signal is congruent between the eyes and the skin. So if we are in extremely bright light, uh, you know, in the midday UV, you want to be covering up both your skin and your eyes. Conversely, if you're trying to build your vitamin D level earlier in the in the day, you don't want to be wearing sunglasses if you've got your skin exposed. So then there needs to be congruence there because there is this neuroendocrine effect from the eyes, from the retina, that that will influence the tanning response. And you're potentially going to increase your or reduce your ability to um respond to this UV light if you're covering up the eyes, because the the eyes think that you're in a low UV environment. The final interesting anecdote, maybe that that I'll mention, is this idea that dietary factors affect photosensitivity. And we know in medicine that drugs affect photosensitivity. Doxycycline antibiotics and the tetracyclines cause photosensitivity. Isotrepinoin, uh, the acne medication absolutely makes people more photosensitive. Certain chemotherapeutic drugs uh you know affect the body's ability to deal with with the stress or the the uh temporary hometic stress of ultraviolet light. So what we've also noticed anecdotally is that if you're consuming or stop consuming dietary sources of uh omega-6 fatty acids, which is you know commonly found, well, abundantly found in uh you know refined restaurant oils uh uh and uh and the like, then that seems to reduce photosensitivity to eat to ultraviolet light. So um that's just an interesting anecdote. There needs to be more data and more research done about that, but it's potentially affecting again what what the body's doing or how the body's responding to to that light. And the body, the body ancestrally had a much higher proportion of omega-3 polyunsaturated fatty acids and omega-6 polyunsaturated saturated fatty acids. So that's no doubt part of the probably the um the formulation of what's going on there.

SPEAKER_00 56:15

I feel like we have gone just partway through a lot of avenues with regards to sun, vitamin D, nutrition, how we perceive it and its impact on the body. But I do think that if everybody listens to the Circadian rhythm episode that I did with Max last week and this one, you're gonna get a general picture of the importance of the basic things that we spoke about for good health and for a healthful pregnancy. Thank you so much for your time and wisdom, Max. Uh in the show notes, we're gonna put all of Max's details there. If you want to look further into the work that he's doing in these areas, you can explore all his offerings online as well. Thanks, Max. That has been this week's episode of the Great Birth Rebellion Podcast, and I'll see you in the next episode. To get access to the resources for each podcast episode, join the mailing list at MelanieThemidwife.com. And to support the work of this podcast, wear the rebellion in the form of clothing and other merch at thegreatbirthrebellion.com. Follow me, Mel, at Melanie the Midwife on socials and the show at the Great Birth Rebellion. All the details are in the show notes.