By the way ... Why we SHOULD add vitamin D to food

VITAMIN D is back in the news, with recent research suggesting that a daily supplement could help protect against respiratory infections — coughs, colds, sore throats and even bronchitis and pneumonia.

This fat-soluble vitamin is found in a number of foods, including oily fish, cheese and egg yolks, but we mainly get it from the sun’s effect on cholesterol in the skin.

Hitherto, much of the interest in this vitamin has been focused on bone strength — it helps the body absorb calcium and phosphates from food.

However, we’re beginning to learn that it has numerous other functions in the body, such as keeping muscles healthy. It may also have a role in preventing cancer and cardiovascular disease — and, it seems, boosting the immune system.

As we all know, the problem in the UK — this small island high up in the northern hemisphere — is that we are not exposed to enough sunshine in winter, so our vitamin D levels are low.

Even before the publication of the latest study, I decided to measure my own vitamin D level with a blood test at the local lab and was surprised to find that at 51 nanomoles per litre (nmol/l), it was close to being insufficient: the normal range is 50 to 200.

This is despite my enthusiasm for boiled eggs for breakfast, oily fish for dinner and a diet that has a steady content of vitamin D, thanks to being married to a dietitian.

So, having previously insisted to all my patients — and readers of this column — that vitamin supplements are a waste of money, I find myself in the midst of an about-turn.

I am now taking a supplement of vitamin D and will do so until April.

But knowing that none of us can be relied upon to take supplements diligently, I also support the clamour for the fortification of foods with vitamin D.

Sadly, most of us cannot afford the time nor the expense of the only alternative: a winter holiday in the sun.