This is an essential vitamin for human health, and helps your body to absorb and regulate calcium and phosphorus. As calcium is vital for bone health and bone growth a lack of vitamin D causes issues like rickets, bone disease and osteoporosis. Modern research has also revealed that vitamin D likely protects against other diseases such as hypertension, asthma, diabetes, MS and cardiovascular disease.
It is becoming clear that many people in the Western world, even those on a ‘normal’ diet, can have a vitamin D deficiency. This is because the main source of vitamin D comes not through food, but through sunlight. The body manufactures vitamin D when the skin is exposed to sunlight – usually the hands, face, legs and arms. Even reasonably short exposure to sunlight, far below the time it would take the skin to burn, gives the skin its chance to produce sufficient vitamin D.
The problem is that many people are now actively avoiding the sun due to cancer risks, using sunscreen or creams which block its beneficial effects, or simply not going out in the sun at all as more time is spent indoors on computers, tablets and phones. In addition those who live in far northern or southern latitudes (latitudes nearer the poles) can have long winters where the sun is very low and beneficial sunlight is naturally less available and heavy clothing is worn. These areas include the northern United States, Canada, and much of Europe.
Other people are at risk of vitamin D deficiency. These include vegans, as the main dietary sources are animal derived foods like liver, sea fish, egg yolks and fortified milk. People with dark skin are also at risk as the pigmentation reduces the skin’s ability to manufacture vitamin D. Obese people too are more likely to have low levels. Older people’s kidneys don’t convert vitamin D to its active form in the body so efficiently, so they are also a risk of a deficiency. In addition, they tend not to go out in the sun as much as younger people do.
“In fact, the risk for vitamin D deficiency in people over 65 years of age is very high. Surprisingly, as many as 40% of older people even in sunny climates such as South Florida don’t have enough vitamin D in their systems.” (1)
The Osteoporosis and Related Bone Diseases National Resource Center has a special interest in bone health for the older population, and makes the following recommendations:
“The body needs vitamin D to absorb calcium. Without enough vitamin D, one can’t form enough of the hormone calcitriol (known as the “active vitamin D”). This in turn leads to insufficient calcium absorption from the diet… [in this case] the body must take calcium from its stores in the skeleton, which weakens existing bone and prevents the formation of strong, new bone.
You can get vitamin D in three ways: through the skin [from sunlight], from the diet, and from supplements. Experts recommend a daily intake of 600 IU (International Units) of vitamin D up to age 70. Men and women over age 70 should increase their uptake to 800 IU daily, which also can be obtained from supplements or vitamin D-rich foods such as egg yolks, saltwater fish, liver, and fortified milk. ” (2)
It has recently also been discovered that women who stop taking birth control pills or other contraceptives containing estrogen see a fall in their vitamin D levels, and those women who are trying to get pregnant or who are expecting should ensure they are getting enough. (3)
In fact, nutrition experts in the UK have recommended recently that everyone over the age of 4 should take 10mg of Vitamin D daily. So why aren’t people getting enough vitamin D? The BBC’s story on the recommendations says this:
” Limited amounts of the vitamin are found in foods such as oily fish, liver, eggs, milk, fortified cereals and fat spreads with added vitamin D… But for most people, the bulk of their vitamin D is made from the action of sunlight on their skin (which contains ultraviolet B radiation).
During autumn and winter, sunlight is in short supply, particularly in countries north of 37 degrees latitude, which is from Madrid northwards. Official estimates suggest one in five adults and one in six children in England may have low levels of the vitamin in their bodies….
A healthy, balanced diet is always recommended and with exposure to summer sunshine, many people may get enough of the vitamin D they need. But some groups of people who are at risk of vitamin D deficiency need extra help with reaching those vitamin D targets. And this new advice suggests we should all consider taking supplements, just in case.
What is the advice in other northern countries, such as Scandinavia? In countries such as Sweden, Norway and Denmark, children and adults are advised to take 10 micrograms of vitamin D supplements a day and this rises to 20 micrograms for at-risk groups and people over 75 years old.”
So, what can you do about this if you think you are at risk? Increasing your skin’s exposure to the sun is the best way. If this is not possible, then vitamin D supplements can be taken. Luckily, such supplements are now widely available.