Using a Vitamin D Supplement During the Winter can Eliminate one Source of Worry
As the winter solstice approaches in the northern hemisphere, people living north of the equator need to remember that vitamin D is a nutrient of concern. Without skin exposure to sunlight, people must rely upon dietary intake of vitamin D. Since very few foods are naturally rich in vitamin D and regulatory agencies restrict the categories of foods and beverages which can be fortified, most people will need to supplement.
Vitamin D deficiency can increase risk for cardiovascular disease. People with vitamin D concentrations below 15 ng/mL (37.5 nmol/L) are 35% more likely to experience a cardiovascular event. Low vitamin D concentrations are associated with metabolic syndrome and symptoms of depression. Low vitamin D concentrations are more often seen among smokers, obese subjects, those with low HDL-cholesterol concentrations and fair/poor self-perception of health, and nondrinkers of alcohol..
Because vitamin D is fat soluble, being overweight or obese might contribute to lower circulating 25(OH)D3 concentrations in the blood. There is a linear increase in circulating 25(OH)D concentrations as adipose tissue is lost by obese men. The main determinants for variability in blood 25-hydroxyvitamin D concentrations in lactating women were: 1) use of dietary supplements, 2) use of oral contraceptives, and season of the year. Changes in adipose volume were not reported.
If one is overweight or obese, weight loss may help increase circulating 25(OH)D3 concentrations. For most people, the more obvious means to maintain vitamin D levels above 50 nmol/L will be to use a vitamin D supplement.
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