Sunshine vitamin must be supplemented in winter

A study led by Professor Susan Sullivan at the University of Maine recently published in the Journal of Nutrition indicates that current recommended daily intakes (RDIs) of vitamin D, the all important vitamin that is made by the body in response to sunshine, are only a quarter of those actually needed by most of pre-menopausal women in Maine, USA (where winter daylight hours are much reduced due to the northern latitude).

The Recommended Dietary Intakes (RDIs) are presently set very low at just 5 mcg (micrograms) (200 International Units (IU)) for people up to the age of 50, 10 mcg (400 IU) for those between 50 and 70, and 12.5 mcg (600 IU) for those over 70.  

The new research concluded that daily supplementation with four times the existing RDI for the under-50s i.e.  20 mcg of vitamin D3, during the winter months, achieved optimal circulating levels of 25-hydroxyvitamin D concentrations (> or = 75 nmol/L) in 80% of participants. The researchers considered that this dose to be adequate to optimize vitamin D status in most young women in Maine.

Click here for the abstract of the University of Maine study.

The inadequacy of the RDI (as compared with the results in this study) is not unexpected. Dr Reinhold Vieth and other leading vitamin D researchers have upheld for as long as a decade that as much as 100 mcg (4000 IU) should be taken daily by those in northern or southern latitudes during the winter months in order to support optimal blood levels of 25-hydroxyvitamin D.

How does this impact Europe?

This is a particularly ‘hot topic’ at this time, because in the case of vitamin D, the RDI for those under 50 years—equivalent to the European Recommended Daily Allowance (RDA)— could become the Maximum Permitted Level (MPL) for all ages when maximum levels are harmonized EU-wide as part of the European Food Supplements Directive. This might occur despite the greater needs of those in the extreme north of Europe who experience much longer winters and less sunlight. Older and darker skinned populations also require higher intake levels.

The ANH is at the forefront of demonstrating the scientific inadequacy of methods being developed to establish MPLs by the European Food Safety Authority (EFSA). These issues have also been raised in a petition to the European Parliament by the Irish Association of Health Stores (See ANH Press Release: ‘Ray of sunlight from ANH/Irish efforts in Brussels’).

Further information on vitamin D: ‘Vitamin D: as close to a magic bullet as you can get?’

Have your say!

If you don’t want unfair restrictions on vitamin D and other nutrients, please sign our online petition at: http://www.ipetitions.com/petition/anh-vitaminrestrictions

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