Vitamin D: Sardines, Sunshine & Supplements

13th December 2008

Katie Bolland, a nutritional therapist practising in Bushey Heath, explains why D stands for Don’t Miss Out…

Vitamin D is a topical subject and for good reason. From being the neglected vitamin (even among heath professionals), relegated to treating rickets and little else, D is fast becoming the vitamin to focus on. Deficiency in D is now being linked to heart disease and cancer, to multiple sclerosis, type 1 diabetes, possibly autism and most recently the common cold. Current research indicates that many of us have less than optimal levels of this essential compound, and a Department of Health information booklet, designed to raise awareness among health professionals, is due to be published imminently.

Vitamin D is primarily known for keeping bones healthy by regulating calcium in the body. It is also involved in the proper functioning of the immune system and helps to regulate hormones. It may even help to prevent obesity, especially the kind around the middle (known as central obesity).

The official recommendation is that vitamin D supplements should be given to children up to at least two and possibly five. Over 65s are also recommended to take D supplements. There is no specific advice for older children or adults, although The Food Standards Agency (the voice of government nutrition policy), now recommends that all pregnant women should take vitamin D supplements. What about the rest of us? Do we get enough?

Vitamin D is made in the skin when it is exposed to the sun – our main source of this new ‘wonder vitamin’. Yes, some sun is actually considered good for us! However, it’s only during the summer that the sun is strong enough to do this – and given the summer we’ve just had it’s not surprising that levels are low. As another winter is upon us, depriving us of yet more sun, we need to know what we can do to give our systems a boost.

Vitamin D is also obtained from food. Oily fish such as sardines (even canned) are a good source and provide a dose (10 ug) equivalent to supplements. You obtain even more vitamin D if you have your sardines canned in tomato sauce. Salmon is also high in vitamin D as is cod liver oil but take care: cod liver oil also contains vitamin A, which, in high levels, can be toxic.

Some vitamin D can also be obtained from eggs, meat (especially beef and liver) and fortified foods such as evaporated milk, cereals and margarines.

Research has suggested that Norwegians, living by the coast, eating oily fish regularly and brought up on cod liver oil have levels of vitamin D that protect against diseases such as multiple sclerosis. Of course, fish oil also contains omega-3 fatty acids; by consuming these you gain a host of other benefits, too.

So… people who eat oily fish, take cod liver oil and are lucky enough to spend time in the sun will certainly have higher levels of vitamin D than people who don’t.

However, if you are vegetarian you could well be deficient; if you are a vegan who does not get much sunshine you will almost certainly need to take supplements or fortified foods to avoid severe deficiency.

If you are darker skinned you are particularly vulnerable to vitamin D deficiency because increased skin pigmentation blocks the ultraviolet light that forms vitamin D in the skin. People who wear traditional clothes that cover them up more from the sun may well be deficient. Babies might not get enough if their mother’s milk is lacking. People with coeliac disease may also be at risk. The list goes on.

Current official advice is that white skinned people do get enough vitamin D as long as they get ‘a little sun’, and are eating an ‘average British diet’ – but what about people with darker skins, and what is an average British diet?

The simple answer is that you do not know for sure if you are getting enough D unless you test for it. There is a well established blood test that can be performed by a private GP, nutritionist or nutritional therapist in private practice. It can sometimes also be undertaken on the NHS. Recommendations can then be made with regards to diet/supplements.

Now that the sun has weakened and the days are far shorter, unless you’re a prolific oily fish eater and take winter beach holidays in the sun it’s worth finding out if you are deficient in vitamin D…

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