Rickets, a disease that we thought had vanished along with small boys being sent up chimneys, is re-emerging. A 2006 study of Paediatricians in the West Midlands found an overall incidence of rickets in approximately 8 children per 100,000, with a much higher prevalence in populations from South Asian, Africa and the Caribbean.
At the other end of the scale, with an ageing population, Osteoporosis is on the rise. The National Osteoporosis Society estimates that 50% of women and 20% of men over the age of 50 will suffer some kind of bone fracture due to Osteoporosis.
Many people are aware that vitamin D is implicated in bone health. Some people know that “You can get it from Sunshine”. A few people know what foods it is found in.
It would appear that almost nobody knows that certain population groups are advised by the Department of Health to take food supplements to increase their vitamin D status.
The European Union has set a Recommended Daily Allowance of 5 micro grams.
Achieving even this amount through diet alone is difficult, as intake of many of the primary food sources has declined over the last few years.
Selected Food sources of vitamins D are:
Half pint of full cream milk…. 0.1 µg
Half pint of semi-skimmed milk…. 0.03 µg
Half pint of skimmed milk……… 0 µg
150 g whole milk yoghurt………….. 0.06 µg
1 Egg……………………………………. 1 µg
85 g Salmon or Mackerel…………….. 10 µg
85 g Liver……………………………………. 1025 µg
The most recent issue of the U.K.’s National Diet and Nutrition Survey shows that the mean intake of children age 4 to 10 is 1.9 µg daily, and those over 65 is 3.3 µg daily.
The Department of Health recommended daily intake for children aged 6 months to 5 years is 7 µg daily, and for those over 65 is 10 µg daily. This indicates a significant discrepancy between actual intakes and the recommended intake.
Evolution has a equipped all animals with the facility to manufacture vitamin D. Birds make it in their feathers, Cats make it in their Fur and Sheep make it from the lanolin in their wool. In Humans a biological process in our skins converts cholesterol into vitamin D.
Homo Sapiens migrated from Africa many thousands of years ago, and those that move further north evolved paler skins to allow effective synthesis of vitamin D from weaker sunlight. This skin reaction will only take place when the sun is at a sufficiently high angle in the sky to provide light with in a specific UV bandwidth.
In the South of the UK (below latitude 52° 17’–level with Cambridge) the sun reaches this intensity for 5 months of the year, from May to September.
North of Cambridge the sun only has sufficient intensity to stimulate vitamin D production for 4 months of the year. In addition, ethnic minorities with darker skin, who have not adapted to living with weaker sunlight, need longer in the sun to stimulate the production of vitamin D. It is estimated that 9 out of 10 adults of South Asian origin are at least sub-clinically deficient in vitamins D.
Sadly,the public health messages of the last few decades warning of skin damage and cancer from exposure to too much sun, has caused people to over react. People now cover up in daylight, limiting their exposure to the sun, and consequently have chronically low levels of vitamin D.
Also, as we age, our skin becomes less able to synthesise vitamin D.
In the UK are currently 89,000 hospital admissions every year for hip fractures caused as a result of Osteoporosis. This works out to a cost of £2.3 billion every year.
90% of hip fractures in elderly are caused by falls. Frequently, it is the fracturing of the hip that causes the fall, not the fall that causes the fracture. The hip joint become so weakened by the Osteoporosis that it simply fractures. A Cochrane review in 2010 found 28% reduction in fractures when a vitamins D supplement was used.
A vitamin D supplement does not cost a lot. A years supply will cost the NHS £25. A year’s supply from a chemist or health food shop can cost as little as £12 per year.