Vitamin D - the most important supplement you can take?
- Gavin
- May 19, 2020
- 4 min read
Hi Everyone,
I hope you’re keeping well! Apologies for the delay between posts. Today I actually want to revisit something I discussed briefly back in March – Vitamin D. It’s so important – especially now, during this pandemic – that it deserves its own post.
Quick summary: Optimal Vitamin D levels are vital for a wide range of processes in the body, including the immune system and ability to fight off respiratory infections. This is something that anyone who does not get regular sun exposure should seriously consider supplementing with. If you’re going to supplement with anything, Vitamin D is a good place to start.
You should also ask your doctor for a Vitamin D test (“25-Hydroxy Vitamin D”, optimal levels are 45-70 ng/mL), or get a home test, to allow you to find the best supplementation dose for yourself.
Full post:
Vitamin D is produced in the skin from UVB sunlight exposure and is transported to the liver and then the kidney where it is changed into an active hormone.
Vitamin D (specifically, D3) appears to be one of the very most important supplements one can take. Indeed, it is the first thing I list on my ‘General Health’ recommendations page. A substantial amount of research has linked Vitamin D levels to a wide range of health outcomes, including bone health and density, cardiovascular health, immune function, and physical performance and injury risk especially amongst older adults. Vitamin D also appears important for optimal hormone levels; a 2010 study found that Vitamin D supplementation led to significant testosterone increases in men.
Vitamin D has been in the spotlight recently due to emerging evidence that it may play a role in determining risk of infection of Covid-19, and death from infection. People deficient in Vitamin D appear to be more susceptible:
The evidence specific to Covid is preliminary at this point, not surprising given how new this virus is. However, a comprehensive review of the broader literature on vitamin D and respiratory tract infections more generally found that “Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants.”
Given these host of benefits, one study even went so far as to say that supplementing with Vitamin D around the world is the single "most cost-effective way to reduce global mortality rates."
Supplementation
The best and most natural way of increasing your Vitamin D levels is regular, moderate sun exposure – 15-30 minutes a day, depending on your skin tone, with as much of your skin exposed as possible. Although prolonged exposure can of course cause skin damage, sun appears to have a host of health benefits which I will cover at more length in a future post.
For most of us, this level of regular sun exposure is difficult to achieve, given that we live and work indoors and live in areas that are often overcast. Thus, many people may benefit from supplemental Vitamin D. It is hard to know exactly how much you should supplement with, without knowing your current levels and how you respond to supplementation. I recommend that you ask your doctor for a 25-Hydroxy Vitamin D test to get your levels checked – doing so is easy and inexpensive. Alternatively, you can complete a home test kit and get your levels checked for $79 here.
Optimal levels are 45-70 ng/mL (or, 112-175 nmol/L). If your levels were below 45 ng/dL, you could consider taking a routine dose of 5000 IUs per day for six weeks and then retesting.
Many people do still supplement without knowing their exact levels. Again, unless you are getting regular sun exposure on your bare skin, chances are likely that you have suboptimal levels. This can be especially true for those with darker skin.
Vitamin D is thought to work synergistically with Vitamin K, particularly for bone and cardiovascular health. Therefore, the best supplements combine D and K together. These are two supplements that I like.
The first is a dropper that allows you to adjust the amount that you are taking; a typical dose would involve 2000-3000 IU (4-6 drops) in the summer and 5000-6000 IU (10-12 drops) in the winter. This is very inexpensive, about $.10 to $.20 per day depending on the dose.
The second offers the convenience of a capsule that contains 5000 IU as well as several different forms of Vitamin K, and Vitamin A. But is more expensive, $1.33/day.
People living outside of the USA can find good Vitamin D supplements via my links here https://www.gavinshealthblog.com/general-health
Again, optimizing your Vitamin D levels is one of the easiest, yet important, things you can do for your health. I encourage you to do it! Thanks for reading!
Gavin
P.S. Regarding the other supplements - Quercetin, Epicor, and Astragalus - that I previously mentioned as potentially beneficial for the immune system: unlike Vitamin D, I want to make it clear that I see these are things to take 'as needed', when you feel you are at higher risk of infection. Continuous high-dose supplementation of Quercetin in particular may eventually cause issues with iron absorption. If you are currently staying at home and limiting possible exposure, supplementation with these is probably not necessary. For me personally, I do take Epicor consistently but save the other two for when I feel I need extra immune support.
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