For all the unchecked randomness in this world, there are at least some things you can count on. The sun always rises and it always gets dark, and that’s something life – all life – has learned to rely on. Our internal clocks, known as circadian rhythms, tend to match up with this established external cycle. In essentially all known forms of life, from the earliest cells and bacteria to plants and mammals, the circadian rhythm is characterized by a period of around 24 hours.
You might recall a previous MDA series on how blue light can affect our circadian rhythms, and what we can do to maintain normal, natural levels and timing of blue light exposure. Long story short – it turns out that our exposure to blue light is akin to exposure to daylight, and getting too much – or too little – at the wrong times can disrupt our natural circadian rhythm and affect the quality of our sleep by changing when melatonin is secreted in our bodies. In other words, blue light is a major human zeitgeber (the ten-dollar word of the day); an exogenous cue that synchronizes our internal clock. But it’s not just light that affects our circadian rhythms.
Read MoreOkay, I’ll admit it. I may have spoken out of turn a couple week’s ago when I tried to completely cover vitamin D in a mere three posts (Deconstructing Vitamin D, Vitamin D: Sun Exposure, Supplementation and Doses, Vitamin D: Confounding Factors). A bunch of questions popped up in the comment boards – so here’s my attempt to tie up the loose ends and cover any further wrinkles in the vitamin D story.
Living in Los Angeles, I am lucky enough to be able to get much of my Vitamin D from sunlight all year round. I still take an oral D3 supplement when I’m traveling, too busy to spend much time outside, feel a sniffle coming on, etc. I take 4-10k IU D3 from Carlson’s drops (2k IU per drop). I prefer to get my D3 from the sun, however. It is not what I know I’m missing that concerns me, but what I don’t know that I may be missing. Sunlight may yield other health benefits beyond just Vitamin D production. Oral dosing with D3 won’t give you these other possible benefits.
And I’ve also noticed that switching from a SAD to a primal diet has dramatically improved my sun tolerance (and put a metabolic disorder–porphyria–into remission.
Read MoreYesterday I recommended 4000 IU of vitamin D each day as a good starting point for most people. Though, it’s difficult – nay, impossible – to provide a perfect, universal prescription for vitamin D3 intake. People, and their lifestyle behaviors and environmental conditions are just too different. It’s like with diet. Everyone does well with the basic building blocks, stuff like meat, fat, vegetables, fruit, and nuts, but the optimal ratios are going to differ for individuals based on genetics, dietary history, activity level, and glucose tolerance. Everyone needs vitamin D, but multiple confounding factors must be taken into consideration to determine the right dosage. To start with? Yes, 4k is a good starting point. From there, though, things get considerably more complicated – as they always do.
Now, I don’t want to overcomplicate things, however. The same basic advice holds: get unfiltered sunlight, avoid burning, and take supplements when sunlight is unavailable. But I do want you to be aware of certain factors – environmental, climatic, dietary, genetic, etc. – that may affect vitamin D3 production, requirements, and availability.
Read MoreFrom the presence of vitamin D receptors in our cells and vitamin D factories in our epidermis, along with the central role vitamin D plays in calcium metabolism, immunity, and gene expression, it’s pretty clear that having adequate vitamin D is an essential component of being a healthy, successful homo sapien. And yet, many health practitioners suggest that vitamin D deficiency is one of the biggest nutrient deficiencies in modern society. The question, then, arises: What’s the best way to get enough vitamin D – via oral supplementation or sunlight?
To determine that, let’s examine a few common questions surrounding the various modes of intake.
Read MoreBefore phototropic plants began bending toward sunlight, before the bikini-clad beach denizens began tanning en masse, and before the first house cat followed the sliver of sunlight around the room all afternoon, our primitive, microscopic marine forebears were flourishing by converting the sun’s energy into chemical energy usable by biological life. You’re probably aware of photosynthesis, the process by which plants, algae, and other organisms do it and produce byproducts like oxygen, but even the unicellular archaea that do not produce oxygen utilize sunlight for energy. And if you aren’t obtaining energy directly from the sun, you’re probably eating the organisms that do. Either way, sunlight directly or indirectly supports all life (well, except for the chemoautotrophs living in deep sea hydrothermal vents feeding off of inorganic energy sources like iron, ammonia, or sulfur).
Read MoreMost people are at least cursorily familiar with the concept of the circadian rhythm. For those who aren’t, the circadian rhythm refers to our internal, approximately 24-hour cycle of biochemical, physiological, and behavioral processes. Every living thing, from fungus to bacteria to plant to animal, has a circadian rhythm. External cues called zeitgebers (what a great word, huh?) help synchronize or alter our rhythms; they include temperature, nutrition, meal timing, social interactions pharmacological interventions (medicines, drugs), and, most prominently, the light/dark cycle of the earth.
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