C. Brot

TL;DR: The depression of the vitamin D-PTH system seen among smokers may represent another potential mechanism for the deleterious effects of smoking on the skeleton, and may contribute to the reported risk of osteoporosis among smokers.

TL;DR: Vitamin D status is low in northern Europe during winter and more than one-third of the adolescent girls have vitamin D status below 25’nmol/l and almost all are below 50 nmol /l.

TL;DR: It is shown, that healthy middle-aged Danish women are prone to vitamin D insufficiency in the winter-spring period, if they avoid sun exposure in the summer period and abstain from vitamin D supplementation.

TL;DR: In this article, the influence of Gc phenotype and Gc concentration on vitamin D status was examined by using isoelectric focusing, and the results showed that Gc was an independent predictor of 1,25(OH)2D whereas Gc phenotypes were a significant predictor of 25OHD, even after adjustment for the effects of season, sunbathing habits, skin thickness, use of vitamin supplements, smoking and body mass index (BMI).

TL;DR: It has been demonstrated that 25OHD is absorbed better and faster from the diet than native vitamin D and has metabolic effects of its own in regulating cell growth and calcium metabolism, which means true vitamin D intake will be underestimated.