Vitamin D Deficiency and Its Health Consequences in Northern Europe

Abstract

Deficiency and insufficiency is common in the Northern, Western, and Central part of Europe. Around 43-92% of adults and 89-97% of teenage girls have plasma 25-hydroxyvitamin D {[}25(OH)D] levels <50 nmol/l. The vitamin D deficiency is caused by low sun exposure especially during winter time and because of the high latitudes in the Northern regions. The lack of solar exposure is combined with a low dietary vitamin D intake especially in the Central and Western part of the continent. The high dietary intake of limy fish, cod liver, and cod liver oil in Scandinavia and Iceland and the frequent use of supplements mitigate to some extent the effect of the reduced sun exposure. Across Europe, epidemiologic studies indicate a positive effect of latitude on average plasma levels of 25(OH)D. However, at the level of the individual country (e.g.. France and the United Kingdom) with a more common fortification policy and supplementation tradition, latitude is inversely related to plasma 25(OH)D. At the individual level, European studies have confirmed that plasma 25(OH)D depends positively on dietary vitamin D. vitamin D supplementation, sun exposure, living in partnership, recent vacations to sunny regions, and sunbed use and inversely on use of sunscreen and covering clothes, smoking habits, and body mass index. Risk groups include breast-fed children, pregnant and lactating women, and older persons. Veiled and pigmented immigrant women with covering clothes and vegetarians constitute a special problem. Vitamin D status can be improved by encouraging safe sun exposure, improving dietary intake, e.g., by fish and cod liver oil, obligatory food fortification, and vitamin D supplements. Nutritional recommendations from governments and other regulatory institutions should be adapted to the present knowledge of the actual need of vitamin D.