Translations:Vitamin D/17/en

A diet with insufficient vitamin D in conjunction with inadequate sun exposure causes vitamin D deficiency, which is defined as a blood 25(OH)D level below 12 ng/mL (30 nmol/liter), whereas vitamin D insufficiency is a blood 25(OH)D level of 12–20 ng/mL (30–50 nmol/liter). An estimated one billion adults worldwide are either vitamin D insufficient or deficient, including in developed countries in Europe. Severe vitamin D deficiency in children, a rare disease in the developed world, causes a softening and weakening of growing bones, and a condition called rickets.