A review published in the BMJ this week suggests that rickets is becoming disturbingly common amongst British children. Rickets is caused by vitamin D deficiency, which is triggered by insufficient sunlight and poor diet. It has been suggested that long periods of time spent indoors are contributing to the problem.
The researchers from Newcastle University suggest that milk and other food products should be fortified with vitamin D. The Food Standards Agency has resisited mandatory supplementation, suggesting instead that pregnant or breastfeeding women and people over 60 should take 10mcg vitamin D each day. They argue that everyone else should be able to meet their requirements from exposure to sunlight and diet. Vitamin D is stored in the body, so excess intake can cause toxicity.
Half of all adults in Britain are thought to suffer vitamin D deficiency in the winter and spring; the situation is worst in the north of England and in Scotland. Asian populations are at greater risk because they cover large areas of their skin; the housebound elderly are also at risk.
To reduce the risks of vitamin D deficiency, the skin should be exposed regularly to sunlight in spring and autumn, but more cautiously in summer. As summer approaches, unprotected exposure should be limited to short spells earlier in the morning and later in the afternoon as direct sunlight exposure is not recommended between the hours of 11am and 3pm to avoid burning. In the uk, winter sunlight does not contain the correct ultraviolet wavelengths for vitamin D production, but production and storage during the summer months should last through the winter.
Vitamin D rich foods can also be enjoyed; oily fish should be consumed three times a week. Liver, egg yolks, meat and milk are also sources of vitamin D.
Vitamin D deficiency is thought to be involved in a number of chronic diseases including mental health problems, cancer and autoimmune disease. To find out more about how to test your vitamin D status Click Here.