06 Nov Vitamin D: Why It’s Kinda A Big Deal
How the actual heck has November 2017 even happened? Who knows. But if you’re north of Equator, you’re probably acutely aware that Winter is wrapping itself pretty tightly around that part of the world. The fact that 3/4 of your colleagues have colds and coughs kinda gives you enough of a clue that “sick season” really is here.
So even though I’ve ended back in my home town in Zimbabwe (for a couple of months) under not my most favourite of circumstances, I’m really grateful to:
a) be escaping sardine-squashed journeys with commuters who apparently don’t appreciate that COVERING THEIR MOUTHS whilst spluttering & sneezing in other people’s personal space is simple common decency.
b) be able to lie on our lush front lawn for 15 + minutes mid-afternoon, lapping up direct light beams from the Southern African Summer sun. Not only does this give me all the warm feeeeeels (literally) but I’m also getting in one of the nutrients most lacking in London (well, the whole UK really) especially at this time of year. You guessed it: our good ol’ buddy Vitamin D.
But what’s the big deal with the D?
Well, given that close to every single cell in the entire human body has a Vitamin D receptor – that speaks volumes of how pretty bang-a-langing it is for health. It plays a role in cell differentiation, calcium absorption & calcium + phosphorus blood balance (strong bones yo!) aaaaand immune regulation (to name but a few).
But before you go chugging back a whole heap of high street Vitamin D supplements, let’s factor a few things in: whilst low levels are properly lame (everything from increased risk of heart attack to autoimmune disease to muscle weakness & pain), having too high levels of the D can do real damage too (we’re talking kidney stones, strokes & low bone density kinda damage).
The UK lab reference range for Vitamin D is 50 – 200 nmol/L, measured as 25(OH)D in blood. However, the Vitamin D Council (yes – there really is a council for Vitamin D), goes a bit further & breaks down the reference range for this fat soluble vitamin as follows:
- Deficient: 0 – 100 nmol/L
- Sufficient: 100 – 200 nmol/L (with an optimal level of 125 nmol/L)
- High Normal: 200 – 250 nmol/L
- Undesirable: > 250 nmol/L
- Toxic > 375 nmol/L
Note: this doesn’t take into account likely variations in optimal ranges for populations of different ethnicity.
And as Dr Chris Kresser points out in one of his articles, it’s important to appreciate a bit of a bigger picture by understanding how Vitamin D is metabolised:
Upon exposure to sunlight, Vitamin D can be synthesised in the skin (from something called 7-dehydrocholesterol). It’s then taken off through the blood to the liver where it undergoes primary hydroxylation, making 25(OH)D – the marker used to measure vitamin D status. It then makes its way to the kidney & undergoes secondary hydroxylation with the end product being 1,25(OH)2D – the active form of Vitamin D.
Here’s the thing: the active form isn’t necessarily a true reflection of nutritional vitamin D status because parathyroid hormone (PTH) tightly regulates the need for it. That’s because if there’s a drop in blood calcium, the PTH stimulates active vitamin D formation so as to increase calcium re-absorption via the kidneys, increase calcium absorption in the small intestine & mobilise calcium from the bones. In short: high PTH can lead to lots of active vitamin D which may lead to low bone mineral density.
So where do we get Vitamin D?
The best source is the sun: anywhere from 15 – 30 minutes in direct sunlight (or as our friends at the VD Council recommend: half the time it takes for your skin to turn pink, should your be of Caucasian ethnicity). More than this will be detrimental to health (and really isn’t recommended) and slapping on loads of sunscreen isn’t ideal either.
Food wise: there are only a few foods that contain vitamin D, namely fatty fish (mackerel, sardines, salmon), fish liver oils, offal, egg yolks (from hens that have been fed vitamin D) & mushrooms (that have been exposed to UV light).
Supplements: if supplementation is indicated, you might need to fork out a bit more for better quality brands, but when you compare ingredients & bio-availability of these to say, those found in your local high street drug store, you’ll soon realise that you’re winning in the long run. Ideally, you’ll want to be getting in D3 (cholecalciferol) as it’s thought to be more biologically active in the body than D2 with K2 for increased absorption.
Test, take the bigger picture into consideration (like parathyroid hormone, calcium levels, micronutrient status, seasons, skin colour), try get in some decent sunlight (this is your permission slip to take a holiday to a sunshiny place), supplement (with proper quality stuff) if indicated and most importantly RE-TEST after 3 – 4 months of treatment because ain’t nobody got time for toxicity.
And given that about 70% of our immunity is found in our gut, if you’ve got your Vitamin D to tip top levels but still have an immune system that’s shot to shit? It’s possible that we might need to dig around a bit in your actual shit (not us personally – the laboratory would do that) whilst getting some other basics in place too (like sleeping more, eating well, stressing less – all those things that we know that we should do but often find it an actual mission to implement).
Soooooo that’s why I’m here (*waves enthusiastically but in a cool way*): to help you figure out what makes your bod flourish & what makes it seem like it’s legit failing you.
My door’s open – contact me and let’s get you feeling like yourself again from your fingers all the way to your toes.
Because life is for the living, and flip, I’d find it a wild privilege to journey with you to the fullness of your heath.