What is with all this talk of Vitamin D?
Vitamin D is a vital substance for the maintenance of strong bones and prevention of conditions such as osteomalacia (softening of bones) and rickets in children. This is because Vitamin D helps the body to absorb calcium; which is the body’s bone building material.
Vitamin D can be obtained by the body in 2 ways. Via exposure to sunlight or through the foods we eat:
- Foods such as eggs and oily fish have a good amount of Vitamin D in them that can be absorbed and used by the body.
- The most effective way to get Vitamin D is through sunshine. Having your skin in sunlight causes a chemical reaction in the body that naturally produces Vitamin D. However to get the daily requirement of Vitamin D from the sun, you would need to spend 10-15 mins every day in full summer sun with bare arms and legs. Not very likely in England.
Due to this lack of sunlight it is very common to be deficient in Vitamin D. Symptoms of this can be: Tiredness, joint/bone pain and a feeling of being unwell. However the symptoms are sometimes vague, and some people may not have any symptoms at all.
Supplements can also be used as a source of vitamin D. Especially for those who are most commonly deficient in Vitamin D: pregnant and breastfeeding women, babies and young children, people aged over 65, and people who are not exposed to much sun – such as people who cover up their skin when outdoors, are confined indoors for long periods or those who work night shifts.
A deficiency in Vitamin D is also more common in the winter months due to the reduction in sunshine. So it is even more important at this time of year, to ensure that you body is getting enough Vitamin D for maintaining healthy bones.
According to Dr. Robert Heaney humans utilize approximately 4000 IUs of vitamin D3 per day. Heaney et al. 2003 Human serum 25 hydroxycholecalciferol response to extended oral dosing with cholecalciferol. Am. J Clin. Nutr. 77: 204-210. Vitamin D deficiency is diagnosed when the serum 25-hydroxyvitamin D (25-OHD3) concentration is less than 20 ng/mL. The simple fact is that humans were never meant to get their vitamin D from food. Genetically humans are designed to get vitamin D from sunlight. As we have outlined above this is simply not a realistic option for most humans living and working indoors or who live in areas where sunlight levels change with the seasons.
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