Vitamin D: time to check your levels?
Should we be paying more attention to our vitamin D levels? The simple answer is yes. Following the release of a government-commissioned report by Public Health England (PHE), recommended levels have been set for a minimum of 10 micrograms (400IU) per day. But why do we need it and how does it benefit health? We consulted leading expert Dr Adam Carey…
What is vitamin D?
Vitamin D is a hormone-like substance but, unlike other vitamins which we have to get from our diet, our bodies can manufacture vitamin D under the right conditions. It is found in small amounts in foods such as oily fish, egg yolks, some fortified cereals and margarine, but most of our vitamin D intake comes from our skin’s reaction with UV sunlight.
Why is it so important?
For many years it was thought that the main role of vitamin D was to help us use calcium to keep our bones strong and healthy. It is certainly true that vitamin D deficiency causes the bone weakness and deformity seen as Rickets in children, and osteomalacia in adults. However, over the last five years a host of studies have emerged, suggesting that the benefits of vitamin D extend way beyond what was previously thought. In fact, receptors for vitamin D (structures on cells that enable substances to enter them rather like a key in a lock) have now been found in almost every cell in the body. This means that vitamin D acts within these cells, affecting a large number of bodily systems and disease risks.
What conditions does it help?
These are now thought to include: bone health, immunity, inflammation, heart problems and blood pressure, diabetes risk, autoimmune diseases, neurological disorders including depression, seasonal affective disorder and dementia risk, body composition and sporting performance.
Are people becoming deficient?
Recent government research suggests that our average daily intake of vitamin D in the UK is as little as 120iu a day. One in seven adults under 65 is thought to be deficient, which rises to one in three over 65-year-olds and as many as 19 out of 20 otherwise "healthy" South East Asians living in the UK.
What are the reasons?
We know vitamin D production depends on the amount of sun exposure a person gets, but from the early 1990s much of the Western world has become wary of the sun to reduce the risk of skin cancer. As a result, this has reduced the peak levels of vitamin D production in the summer months and in the winter months we make very little or no vitamin D in the UK as the sun is too low in the sky to be of any benefit.
Should you supplement your diet?
Vitamin D levels rise and fall throughout the year. Most of us will reach a peak level towards the end of summer which tails off towards the end of winter. It is a good idea to get your vitamin D levels assessed to identify any fluctuations in levels throughout the year, so that if you do need a supplement, you take it at the appropriate level. Some people may need no support in the summer, but require supplements in the winter, while others may benefit from supplementation at different levels throughout the year.
Can you get levels assessed?
Tests may be available at your GP surgery and a number of internet sites now offer testing. Getting your vitamin D levels tested is a simple process involving a finger prick test, which is then sent to a laboratory.