D3 Supplementation
Why I stopped taking vitamin D pills
Whether or not vitamin D should be taken orally has been discussed for many years & there is plenty of evidence for both sides. Vitamin D is a hormone at the end of the day & thus effects people in a wide variety of ways. There seem to be many cases & examples of vitamin D toxicity while many others report no ill effects. I’ll present what I’ve read here with sources for everything & you may weigh the information for yourself & talk to a doctor.
Exogenous vs Endogenous
Supplemental vitamin D is not the active form, it must be converted to active vitamin D in the kidney using magnesium and riboflavin. Vitamin D endogenously produced via sunlight goes through the conversion process where there are many forms of pre-Vitamin D, I will not go over all of those.
Vitamin D is fat-soluble, meaning it needs to be escorted by a protein through the blood — which is polar. When we produce vitamin D endogenously, it is estimated that 100% of it is carried to the liver and kidney using D-Binding Protein (DBP). Exogenous vitamin D (from diet and oral supplementation) is absorbed within the intestine by chylomicrons and once in the bloodstream it is carried by lipoproteins in addition to DBP. This distinction in carrier results in a low and sustained delivery of Vitamin D when produced endogenously in contrast to a rapid and less-sustained delivery of exogenous vitamin D1. I suspect that this difference in carrier also relates to accumulation in joints and bone, a possible source of many complaints of joint pain.
Considering exogenous vitamin D's possible role in cardiovascular disease was interesting. Since exogenous vitamin D is carried in part by lipoproteins, it has the potential to build up on artery walls and contribute to lesion formation. This paper summarized the theory well2.
Hypercalcemia
Vitamin D supplements and fortified foods were first introduced after an increase in rickets was observed in infants. While this supplementation was beneficial for many, it also caused a rise in hypercalcemia and vitamin D toxicity which lead to the banning of vitamin D-fortified foods3.
The sun is the best way to produce vitamin D and what's interesting is it's impossible to experience toxicity when producing it endogenously; vitamin D takes on so many forms before it is fully activated that it is easily degraded back into these, which do not cause that release of calcium4. Oral D3 does not have negative feedback control and causes a large release of calcium, it can overload the kidney taken in high dose, using up magnesium and B2 to convert it all into the active form.
I believe a portion of the toxicity symptoms that arise from vitamin D supplementation stem from the large concentration circulating all at once, as opposed to the gradual & varying production experienced naturally, especially when exposed to the rise & fall in intensity of the sun’s light throughout the day. Studies have determined that peak levels of endogenous D3 levels arise within a few hours following UV exposure5, which is much easier for the body to process versus a high dose all at once.
Aside from the physical effects of supplementation, I noticed a bad habit develop for me personally in that after supplementing my Vitamin D in the morning I would no longer prioritize the need to get sunlight that day, even whilst knowing that the supplement cannot be substituted for sunlight. The body recognizes vitamin D levels as a measure of sunlight exposure & reacts accordingly.
I have found the writings of Dr. Jack Kruse very interesting for this subject. Vitamin D supplements introduce an isolated form of the molecule which holds no kinetic energy. When you produce vitamin D from sunlight exposure, kinetic energy accompanies it & thus you feel the warmth of sunlight. That kinetic energy is not simply bringing heat to the body, it is also capable of effecting electron spins & orbitals. These effects influence not just the conversion of cholesterol to vitamin D, but processes in the mitochondrial ETC & ATP production67.
"Taking supplemental D3 is like trying to hire someone else to do your pushups for you" - Dr. Jack Kruse
Flawed Studies
Regardless of whether or not you believe oral D3 supplementation is beneficial, there is an important idea to consider here. Many studies are done in rodents, which are nocturnal animals. Effects shown in rodents cannot be applied directly to humans especially when the subject matter directly involves the hundreds of pathways involved in circadian regulation, sunlight, & sunlight-effected molecules like vitamin D. Regardless of whether the conclusion of the study is pro-supplementation or against, this is essential to consider.
Also important to note: vitamin D is fat soluble and will be stored in fat to be used throughout the winter. Therefore, upping sun exposure throughout summer months can be sufficient to get through winter with limited sun hours8. Continuing on this point, oral D3 does not need to be taken everyday and its levels may remain high for weeks, depending on the person9.
Big take aways
Supplemental vitamin D is rapidly distributed compared to endogenous vitamin D, and can overload the kidney in large amounts. If supplementing, large doses of vitamin D solely can lead to toxicity over time. However, there are plenty of studies showing great benefit of taking vitamin K2 to help direct this release of calcium. Here is a review discussing the idea that the heart of vitamin D toxicity stems from Vitamin K deficiency10.
Exogenous vitamin D depletes Mg11 and likely also B2 due to its role in conversion to the active form. If the rapid delivery of exogenous vitamin D depletes B2, the production of other steroid hormones can also be compromised12. However, this can likely be mitigated by simply supplementing Mg and B2 along with Vitamin D.
Exogenous D3 supplementation can raise levels for weeks depending on the person, and daily supplementation may be a partial cause of the negative side effects, overloading the body with D3, calcium, and depleting Mg.
Discussion
Convincing anyone to stop oral supplementation of vitamin D is not my intention. By my own standards I believe more evidence is needed to make sweeping statements saying everyone should stop supplementation. Sunlight has an extremely complex effect on skin pathways, bodily functions, and gene regulation which we do not yet understand fully. I do believe that the more we elucidate the connections between all vitamin D metabolites and molecules like dopamine, melatonin, melanin, DHA and many others, the more we will understand why D3 must come from the sun.
I'm not here to tell anyone what to do, just to present the evidence that made me stop supplementing. Everyone needs to weigh the pros and cons for themselves depending on their need and latitude. For people far away from the equator or people who live in areas with little sunlight, it may be of higher risk to allow vitamin D deficiency to persist rather than worry about toxicity from supplementation. For me, I would turn to a sun lamp before going back to oral D3.
Sweeping statements should probably not be made here, I made one in my original tweet as a partial attempt to shitpost, yet I seemed to inadvertently provoke an underground population of supplement enjoyers. Others seemed to misconstrue my words into thinking I was hating on vitamin D altogether, which is just ridiculous. I do stand by my statement, and I believe more studies are needed which consider & identify the differences between people who react poorly to supplementation and people who recognize no negative effects. It is entirely possible that I am wrong, but I have a hard time believing that vitamin D supplements are so safe when we must take supplements like K2, Mg, and B2 along with it to avoid harmful effects. Ideally it is of course best to get vitamin D from the sun, but if this is impossible due to location it is likely better to supplement than exist in a deficiency.
I don’t think I'm presenting any information that is super groundbreaking, this topic has been discussed for a long time. I was not expecting even a small fraction of the reaction I received to the tweet, though it may have just been easy to meme about.
If you want to supplement vitamin D, the studies show it will be best handled in the body with additional supplementation of K2, Mg, B2 and possibly Vitamin A.
This is the information that caused my decision to rely solely on sun exposure for vitamin D, but everyone's situation is different and you must decide for yourself.
I do wonder how safe exogenous D3 can be if it requires the supplementation of a bunch of other stuff to limit toxicity. There is a reason the primary source of which we are designed to rely upon is endogenous production from sunlight, I don't think a supplement will ever be capable of properly replicating this. I'll leave it at that.