Vitamin D Revisited

New research shows that vitamin D may help sustain muscle mass, but we also once more need to talk about vitamin D supplementation in general.

Putting The D Into Muscle

It isn’t that long ago that I wrote an article about vitamin D supplementation and, gasp, actually went as far as recommending it. That didn’t exactly make the earth shake, but if you read some of my supplement articles, you know that I’m not really a friend of vigour, health and happiness out of a bottle.

Now bodybuilders and everyone else interested in bulging heaps of bulges have another reason to look at vitamin D. Researchers at Hartford Hospital, Connecticut,  took more than 400 people and, after taking care that factors like age, gender, fitness level, body mass index etc. didn’t interfere, found that people with higher levels of vitamin D had stronger arms and legs. Best of all, it seems to mainly affect fast-twitch muscle fibers – those that have to get bigger to become stronger.

But, as always, take the findings of a single study with a grain of salt. Why vitamin D, that is usually more associated with bone strength, influences your muscle mass is up for discussion and future research may clarify this.

Discrepancies Abound

Especially because there are still so many open questions about vitamin D. As you may recall, in my earlier article I discussed that the current tolerable upper limit  may be set too low, given how much vitamin D our bodies generate by just spending half an hour in the sun without it apparently causing any ill effect.

I kept tossing that discrepancy around in my head: why don’t many more people suffer from acute vitamin D overdosing, when the body generates so much of it in such a short amount of time? Vitamin D is a fat-soluble vitamin and having those in huge amounts is usually not a good idea. Yet especially people in southern climates, who are often exposed to a lot of sunlight, should be up to their ears in vitamin D.

Apparently nature lets us safely store heaps of vitamin D when a lot of sunlight is available (summer) and then use these reserves when needed (winter). Which from an evolutionary point of view would make sense and also explain why vitamin D overdose is a very rare occurrence, despite it being a fat-soluble vitamin.

On the other hand, we don’t see the most common symptom of vitamin D deficiency, osteomalacia, as often as should be the case, if those  pounding home that we severely lack vitamin D were correct.

To D Or Not To D?

Research about vitamin D generally is still limited and, to be frank, the more I look into this issue, the more amazed I am at how limited it is. Vitamin D still has not gotten quite the attention it should; how much of it is too much and how little is too little are both still completely open for discussion.

We in the northern hemisphere, especially those of us often indoors, do get little of it, so I’m not quite ready to retract the one and only true supplement recommendation I ever made. But let me qualify that statement by saying that all of the current claims about what vitamin D can do should be taken with some scepticism and that getting your vitamin D level checked before supplementing it probably is a good idea.

Picture courtesy of Christopher Brown.