Two studies have highlighted issues with vitamin D intake in Europe. Currently, few countries have dietary recommendations for vitamin D because our bodies can make vitamin D in response to
sunlight. However, there is now concern that significant numbers of people are at risk from vitamin D deficiency, also called hypovitaminosis D.
A UK study measured the vitamin D content of blood samples from 7500 adults aged 45 years, finding a poor vitamin D status in nearly half of the group. Men tended to have a better vitamin D
status than women. The risk of vitamin D deficiency was higher in winter and spring than in summer. Obese people were twice as likely to have a low vitamin D status than lean people. People who
ate oily fish or took vitamin D supplements had the highest blood concentrations of vitamin D (measured as 25-hydroxyvitamin D). The authors noted that: “Prevalence of hypovitaminosis D
in the general population was alarmingly high during the winter and spring, which warrants action at a population level rather than at a risk group level”.
Similar findings were reported by a Dutch survey of 540 people aged 60-87 years. Blood samples taken during winter showed that over 50% of subjects had a low vitamin D status, as measured by
25-hydroxyvitamin D. Overweight people and those who spent less time being physically active outdoors were more likely to have a poor vitamin D status. A regular intake of fortified margarines,
oily fish and vitamin D supplements were all associated with better vitamin D status. However, the researchers pointed out that so few foods offered a rich vitamin D source that the combined
effect of margarines, oily fish and supplements was fairly minimal. It was concluded that consumers find it difficult to achieve an adequate vitamin D status due to a lack of good dietary
sources and policies, especially in Northern countries, should address this.
For more information see
Hypponen E & Power C (2007). Hypovitaminosis D in British adults at age 45 y: nationwide cohort study of dietary and lifestyle predictors. American Journal of Clinical Nutrition. Vol 85,
issue 3, pg 860-8.
Van Dam RM et al (2007). Potentially modifiable determinants of vitamin D status in an older population in the Netherlands: the Hoorn Study. American Journal of Clinical Nutrition, Vol 85,
issue 3, pg 755-61.