Robert Baker: Long may we keep on taking the tablets: let's just steer clear of polar-bear liver

Should the sale of vitamins and supplements be more tightly controlled? It seems pointless when they're so harmless. We live, though, in the age of evidence-based medicine, and just being harmless isn't good enough any more. If you are selling a product for health purposes then you have to show that it does some good, and more importantly, ensure that your rules are harmonious across Europe. Why should we Limeys be able to buy boron, sulphur and vanadium when our German cousins need a prescription?

Vitamins do, of course, contribute to health. The word, coined by a Polish scientist called Funk, derives from the contraction of "Vital Amines", because he believed them so essential to life. Vitamin deficiencies have been known about for centuries. Hippocrates described the symptoms of scurvy – deficiency of Vitamin C – in the fifth century BC. Columbus named Curaçao (cure) after the miraculous recovery of his sailors left to die there. Most Brits know why we used to be called "Limeys".

While scurvy is now rare, doctors prescribe vitamins for properly diagnosed deficiencies. There have been moves for some years to fortify bread with folic acid to prevent birth defects; adding Vitamin B1 to beer to prevent brain damage has been proposed recently. In my own practice it has recently been realised that Vitamin D deficiency contributes to susceptibility to TB among darker-skinned people.

However, the evidence that supplements do any good for otherwise healthy people is less strong. In excess, vitamins and trace elements may even be toxic. Every Trivial Pursuit player knows that you should not eat the liver of the polar bear because of its deadly load of Vitamin A. But that is not the motive behind this ruling.

My view is that it is fatuous. Dr Caroline Jackson, a Tory MEP, has said: "MEPs are receiving dozens of letters from desperate people who believe their health depends on being able to buy these products." I think the key word here is "believe". There may well be a placebo effect; besides, we are supposed to be encouraging patients to take responsibility for their own health. If that means taking harmless boron pills, then so be it. Do the Germans have to reciprocate by developing a Common Eurobowel obsession, like ours?

Deficiency of vitamin B1, common in red wine drinkers, can cause an odd sort of psychosis characterised by confabulation – making things up to cover their brain damage. I wonder if the legislators of this Bill had considered popping some B1?

The author is a doctor in a London teaching hospital