A diet with insufficient vitamin D in conjunction with inadequate sun exposure causes vitamin D deficiency.
Severe vitamin D deficiency in children causes rickets, a softening and weakening of bones, which is a rare disease in the developed world.
), the human body cannot synthesize vitamins on its own in sufficient amounts and must, therefore, ensure a steady supply through the diet.
Vitamins are micronutrients that do not provide energy (like macronutrients) but instead have very specific biochemical roles.
Rickets, a childhood disease, is characterized by impeded growth and soft, weak, deformed long bones that bend and bow under their weight as children start to walk.
This condition is characterized by bow legs, Although rickets and osteomalacia are now rare in the UK, outbreaks have happened in some immigrant communities in which osteomalacia sufferers included women with seemingly adequate daylight outdoor exposure wearing Western clothing.
Its discovery was due to effort to find the dietary substance lacking in children with rickets (the childhood form of osteomalacia).
The binding of calcitriol to the VDR allows the VDR to act as a transcription factor that modulates the gene expression of transport proteins (such as TRPV6 and calbindin), which are involved in calcium absorption in the intestine.
PY - 1982/1/9Y1 - 1982/1/9N2 - To determine the effect of increased skin pigment on the cutaneous production of vitamin D3, circulating vitamin D concentrations were determined in two lightly pigmented Caucasian and three heavily pigmented Negro volunteers after exposure to a single standard dose of ultraviolet radiation (UVR).
Exposure of Caucasian subjects to 1 minimal erythemal dose of UVR greatly increased serum vitamin-D concentrations by up to 60-fold 24-48 h after exposure, whereas this dose did not significantly change serum vitamin-D concentrations in Negro subjects.