Vitamin D. Sunlight
Rickets returns to the UK
A few foods, such as oily fish (sardines, left) are good sources of vitamin D.
But the main source (right) is not food; it is regular exposure to sunshine
Our news team reports Rickets, the disease that weakens growing bones and makes legs bowed, is often thought to be one of those ' classic' deficiency diseases like beri-beri, pellagra and scurvy, that continue to diminish and have now virtually disappeared. Wrong. It remains fairly common in some lower-income countries; and rickets has now reappeared in the UK and is becoming more common.
A recent report in The Guardian (1) states: 'England's chief medical officer, Dame Sally Davies, is concerned that young children and some adults are not getting enough vitamin D… She is to contact medical professionals about government guidelines which recommend that some groups, including under-fives, may require daily vitamin D supplements… Research last year suggested that a quarter of Britain's toddlers did not have enough vitamin D in their bloodstreams'. Official guidelines say children and pregnant women should have 400 units a day of vitamin D. The US guidelines recommend 4,000 units.
Commenting, World Nutrition editor Geoffrey Cannon says: 'It is indeed true that vitamin D is naturally contained in a very few foods, such as oily fish, such as the sardines shown in the picture above, left, and is added to a few others, notably margarine. In Britain during and after the Second World War and afterwards, cod liver oil, together with orange juice to fend off scurvy, was supplied to mothers for their children. But recommending supplements now, as the UK government and many paediatricians do, while this is essential in cases of evident deficiency, misses the point. The main source of vitamin D is not food, it is sunshine'.
In last August's issue of World Nutrition, the author and campaigner Oliver Gillie states emphatically that practically all people who live in northern climates, should sunbathe regularly, to ensure healthy levels of vitamin D, and to prevent diseases of the bones and other organs (2). This is especially important for dark-skinned people and those who live in cool cloudy climates, with thin sun like that shown in the picture above (right). He also states that advice to avoid sunshine to prevent skin cancer is an error. His final advice is shown in Box 1.
Box 1
Oliver Gillie's SunSafe advice
- Sunbathe safely without burning – every day if you can.
- The middle of the day is a good time for sunbathing in high latitudes because UVB, which generates vitamin D in skin, is most intense at this time.
- Remove as many clothes as you can. Start by sunbathing for 2-3 minutes each side. Gradually increase from day to day to a maximum of half an hour per side in high latitudes, less elsewhere.
- Be cautious. Remember intensity of sun varies with season, time of day and cloud, and allow for differences between individuals in skin tone. Never bake
- Do not use sunscreen creams while aiming to boost vitamin D.
- If feeling hot or uncomfortable, expose a different area, cover up, or move into the shade. If continued exposure cannot be avoided, as in some sports, use sunscreen cream
- The face is easily over-exposed so it makes sense to wear a hat when sunbathing.
- Be very cautious under intense sun such as tropical, sub-tropical and Mediterranean summer conditions, or similar. Expose your body for much shorter times until you find out how much is safe. A few minutes in direct midsummer sun will be sufficient to begin with.
- In intense sun wear a hat and use sun-cream to protect the top of the feet which easily burn because they present their surface perpendicular to the sun. Sensitive people will need to wear long sleeved shirts and long trousers when going out in the middle of the day but these parts are less at risk because they do not present a perpendicular surface to the sun.
- Children benefit from sun exposure, but need guidance
- A tan is natural and is generally associated with good health
Notes and References
- Campbell D. Vitamin D awareness in decline, say doctors. The Guardian, 25 January 2012.
- Gillie O. Let the sun shine on you.[Commentary] World Nutrition, August 2011, 2, 7: 308-332. Obtainable at www.wphna.org
