This article presents an overview of the recommended vitamin D levels and how these vary level across Europe and across different age groups.
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Vitamin D and Greeks: some facts and figures
Vitamin D status in Europe shows surprisingly wide variation; for example the 1997 SUVIMAX study in French adult men and women aged 35-65 years showed an average of 43nmol/L in the North, which is classified as insufficient by modern standards, and 94 nmol/L in the South West of France, (classified optimal by modern standards as it was >80nmol/L). This is as might be expected with the known variation of vitamin D status against latitude. In contrast the 1995 Euronaut-Seneca study on independent elderly people showed a greater vitamin D level in the North of Europe compared to southern Europe, however, both latitudes were classified sub optimal by modern standards and may have simply reflected the generally poor Vitamin D status of elderly house-bound people irrespective of latitude.
Further research from the International Osteoporosis Foundation in 2009 suggests that there may actually exist a paradoxical north-south divide within Europe, where the vitamin D status is better in the north than in the south. However, it is strongly suggested that this may be a reflection of the greater number of non-western immigrants in the south.
With respect to the Greek population in Greece, research shows that vitamin D status is not optimal in a population that enjoys much more sunshine than the UK. It shows that there are deficiencies throughout the various age groups studied including young children, adolescents and adults. The results were as follows:
Newborns: research in 2005 showed that neonates who were breastfed exclusively during the first 6 months of life were in need of vitamin D supplementation irrespective of the time of year. This is surprising in a sunny country like Greece where there is no national vitamin D food fortification programme. Of note also was that the mothers in the study were borderline optimal in the summer and insufficient in the winter. This was confirmed in a separate study in 2006 and concluded that pregnant women should be prescribed vitamin D during pregnancy.
Adolescents: research in 2005 showed that 47% of adolescents aged 15-18 had dangerously low levels in winter whilst in the summer they were all optimal. They concluded that adolescents living in urban areas are at high risk of vitamin D deficiency in the winter.
Elderly: research in Athens elderly in 2007 showed that at the end of winter, about 20% of the group had dangerously low vitamin D levels in winter. Their status improved in summer but 64% still had insufficient levels below the accepted optimal summer level. Factors such as atmospheric pollution were not controlled and may be a significant cause of reduced vitamin D production.
If the research above on Greek people shows that sunny Greece also suffers from vitamin D deficiency then it suggests that Greek immigrants in the UK may be at increased risk of vitamin D deficiency due to the more northerly latitude of the UK.
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