90 percent of Swiss men have less than 30 ng of vitamin D in the winter
Vitamin D levels and associated factors: a population-based study in Switzerland.
Swiss Med Wkly. 2012 Nov 26;142:0. doi: 10.4414/smw.2012.13719.
Guessous I, Dudler V, Glatz N, Theler JM, Zoller O, Paccaud F, Burnier M, Bochud M.
Community Prevention Unit, Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital, Lausanne, Switzerland; [email protected].
QUESTIONS UNDER STUDY:
To update the prevalence of vitamin D insufficiency and to identify factors associated with vitamin D status in the Swiss adult population.
METHODS:
Data from the 2010-2011 Swiss Study on Salt intake, a population-based study in the Swiss population, was used. Vitamin D concentration in serum was measured by liquid chromatography- tandem mass spectrometry. Major factors that influence vitamin D levels were taken into account. Survey statistical procedures were used to estimate means and prevalences of vitamin D levels and status. Monthly-specific tertiles of vitamin D and ordinal logistic regression were used to determine the associations of covariates of interest with vitamin D status.
RESULTS:
The prevalences of vitamin D insufficiency (serum 25-hydroxyvitamin D: 20-29.9 ng/ml) and deficiency (<20 ng/ml) were the highest in the January-March period; 26.4% (95%CI: 21.6-31.7) and 61.6% (95%CI: 56.0-67.0), respectively. In the same period, more than 9 of ten men were vitamin D insufficient or deficient. Each unit increase of Body Mass Index was associated with an 8% decreased likelihood of being in a higher vitamin D tertiles. Oral contraceptive, altitude, urinary excretion of calcium, use of vitamin D supplement or treatment, high wine consumption, physical activity were associated with vitamin D tertiles. Compared to the French-speaking region, the Italian-speaking region was independantly associated with a higher likelihood of being in higher vitamin D tertiles (OR: 1.66, 95%CI: 1.14-2.43).
CONCLUSIONS:
Low levels of vitamin D are common among Swiss adults, in particular during winter months and outside the Italian-speaking region.
PMID: 23188555
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Vitamin D vs season

Vitramin D histogram for each language region - all weights

Vitamin D histogram for language region - just obese

See also Vitamin D Life
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