Deficiency in vitamin D
Wednesday, 18 November 2015 | Stuart
If we can produce so much vitamin D for free from brief but daily sessions in the sunshine, why then are so many of us deficient, especially in the colder months? First of all we need to remember that the required UVB rays are blocked by glass (so sitting in the conservatory, by the office window or in a car doesn’t count), as well as clothes, sunscreen, cloud cover and smog. Suddenly it seems much clearer: how many of us really allow skin exposure to the necessary levels of sunshine? The consensus guidelines produced by the prominent charities above suggest that, although there are many factors involved that need to be taken into account, we need to be exposing one third of our body to the sun, without sunscreen, for just under 15 minutes every day, without, of course, getting burnt. What’s more, to ensure we are getting sufficient UVB rays, we may need to be making use of the midday sun for our daily vitamin D top up, with the highest level of UVB available between 10am-2pm.
We have been frightened off such naked exposure to the sun, although it is now also emerging that the vitamin D we produce from the UVB spectrum may help protect us from the harmful UVA rays when we allow moderate exposure of our bare skin to the sun.
Perhaps the more surprising news, however, is that those of us in temperate regions such as northern Europe are naturally deprived of the crucial UVB rays from October until April. So walking and sitting outdoors in the winter sun may still bring other benefits in terms of sunlight exposure, but vitamin D production is not one of them.
It has been suggested that if we produce sufficient quantities of vitamin D during the summer, then we may be able to maintain lower but basic levels through the rest of the year6. With the current culture of covering up either with clothes or sunscreen during every minute of our summertime sun exposure, I wonder how many of us are achieving sufficient sun stores of vitamin D in the summer months to see us through. For much of the year, then, we may need to be supplementing our sunshine stores of vitamin D.
We have a number of articles about different aspects of Vitamin D and the vital roll it plays. Click of any link below to look at that subject or, below the links, click to bring up a printable PDF document covering all of the subjects by the excellent Nutrigold company, which also incorporates references.