There are some people who really like the idea that taking vitamins and minerals can keep them healthy. There are others who take great pleasure in being sceptical about them. The reality is frustrating for those who like to check out the facts, because although supplements are a multi-billion industry there is surprisingly little data on how well they work. A typical case is the suggestion that biotin can make your nails less brittle.
Biotin – What is it?
Biochemistry is full of funny little molecules like biotin. They are present in small quantities and do obscure but often vital jobs which most of the time we hardly notice. The usual scientific shorthand for this is a cofactor. The details of how a cofactor works can sometimes be a bit obscure. In the case of biotin it binds strongly to some proteins and this helps somehow.
Anyway, I think for our purposes all we need to know is that biotin is a vitamin that we need in our diet. It is sometimes called vitamin H, though I think the concept of a vitamin is getting a bit past its usefulness now so I prefer to think of it as a micronutrient. It is something that is necessary to a healthy life, but we get plenty of it in our diet and so we can basically ignore it on a day to day basis.
Biotin for Nails?
But might it be useful in the case of people with brittle nails? It is used for this purpose in horses. Horses have very different diets and very different nail structures to humans, but might the same basic idea work for us? It doesn’t seem too far fetched. While biotin isn’t a problem for most of our body our nails are at the extremes and don’t have as good blood supply so perhaps giving a boost to biotin levels would help.
But of course science isn’t about how good an idea is, it is about how good the data is. This is an idea that is easily testable. All you have to do is give a large group people a biotin supplement and another similar group a placebo and then monitor whether the treated group has less brittle nails. So off I went to Google to find the trials.
Data on Biotin and the Nails
Unfortunately I didn’t find exactly what I was looking for. I did find some work. In fact I found three studies. All gave positive results, but all three had drawbacks. One was a retrospective study. This means that they looked at people who had taken biotin and looked at their nails. This is okay, but loses a lot of potential information. You don’t know for sure whether the effect was actually from the biotin or some other source. Another trial also showed good results, but didn’t have a placebo. A trial without a placebo can’t necessarily be dismissed as totally useless. But we do know that many treatments have a very strong placebo effect, so you can’t be sure that this isn’t all that you are picking up. Only one of the three trials had any placebo. This trial involved 32 people which is pretty small by any standards. The power of the trial was weakened still further by having three different treatment regimes rather than two. You don’t get something for nothing in statistics. If you split the trial into three rather than two the chances of the results being wrong increases.
Does Biotin Work?
But in all cases the trials while flawed did give positive results. How much weight you put on the data is largely down to your personality. If you have an optimistic frame of mind you might be happy to take a chance. If you are cautious I think you’d be justified in dismissing them. What do I think? I think I’d give this treatment a miss until there was better back up for it. But the thing that interests me is the people who are selling the supplements. Compared to how profitable these treatments are, carrying out a proper trial would not be enormously expensive. I wonder why they don’t?
That maybe is another blog post.
Cutis. 1993 Apr;51(4):303-5. Brittle nails: response to daily biotin supplementation. Hochman LG, Scher RK, Meyerson MS. (Small study (35) with positive results, but was a retrospective study which is weaker than a prospective one.)
J Am Acad Dermatol. 1990 Dec;23(6 Pt 1):1127-32.Treatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopy. Colombo VE, Gerber F, Bronhofer M, Floersheim GL. (A very small trial but with good results.)