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How to get enough Vitamin D

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Visual Guide: Why we need vitamin D

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Vitamin D plays an important role to maintain parts of the body in good health but how can we know if we have enough vitamin D, where does it come from and what exactly do we need it for?

The sunshine vitamin

Our body can make vitamin D from sunlight when the UV index is higher than 3. Sunscreen protects our skin from burning but it also blocks vitamin D production. It's not always possible to make vitamin D from sunlight particularly in winter when the UV index is low.

What does vitamin D do?

The basic function of vitamin D is to regulate blood levels of calcium and phosphorus, helping to build strong bones and healthy teeth.

New research indicates that this is only the tip of the iceberg.

We get more colds in the winter when we are exposed to less sunlight. This might be due to low levels of Vitamin D. It is also suggested that lower levels of vitamin D reduce the brain's production of serotonin, which lowers mood.

Vitamin D deficiency

A study of nearly 300 hospital patients (of all ages) found that 57% of them did not have high enough levels of vitamin D. The EU recommended daily allowance (RDA) of vitamin D is 200IU per day. As our ability to make vitamin D - like many things - declines with age, there are new recommendations from America suggesting intakes should increase as we get older.

Risks of deficiency are increased if you live at high altitude, you have dark skin pigmentation or you are obese.

Can supplements help?

"An intake of 800-1,000IU is well tolerated and longer term studies suggest this is likely to be close to new recommended levels," says Professor Adam Carey.

Besides reducing the incidence of the common cold by 70% over 3 years, vitamin D supplementation has been shown to reduce the risk of dying from heart disease by 30% in patients with known risk.

The Nutrition Expert editorial team compiles articles with the help of Healthspan's experts to answer key questions from our community as well as researching common health topics and news.

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  • References and links

    (i)   Ginde AA et al.Arch Int Med 2009; 169(4):384-390
    (ii)  Lansdowne AT et al. Psychopharmacology (Berl). 1998;135(4):319-23
    (iii) Thomas MK et al. New England J Medicine 338(12):777-783 (Mar19, 1998)
    (iv) Ruxton CHS, Derbyshire E. Nutrition Bulletin 2009;34:185-197
    (v)  Li-Ng M et al.Epidemiol Infect. 2009 Oct;137(10):1396-404.Epub 2009 Mar 19 Tami L Bair et al. Circulation. 2009;120:S455

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