Authors :
Hicham Chemsi; Naima Khlil; Samir Ibenmoussa
Volume/Issue :
Volume 6 - 2021, Issue 9 - September
Google Scholar :
http://bitly.ws/gu88
Scribd :
https://bit.ly/3lksjKB
Abstract :
Vitamin D appears today as a vitamin with a
multiple potentials. It’s involved in many physiological
processes. It was for a long time confined for its role in
phosphocalcic metabolism. Due to its dual food and
endogenous origin, vitamin D constitutes a contributions
and needs remain difficult to define and are currently
under debate. On the other hand, the metabolism of this
vitamin D is better known. Its metabolism involves a first
hepatic hydroxylation leading to the formation of 25-
hydroxyvitamin D 25OHD as well as a renal
hydroxylation resulting in the formation of 1,25(OH)2 D,
the active metabolite of the vitamin D. Vitamin D
deficiency is defined by a serum 25OHD concentration
below 20 ng/mL. On the other hand, the insufficiency in
vitamin D is defined by a concentration between 20 and
30 ng/mL. The deficiency and insufficiency are very
frequent situations associated with an increased risk of
developing various pathologies. The effects of vitamin D
supplementation on reducing the risk of fractures and
falls are documented by various intervention studies. The
other potential extra osseous effects of vitamin D are
mainly documented by observational and experimental
studies. Although there is not yet a consensus on the need
for vitamin D. All experts agree that the recommended
dietary allowance is very insufficient and should be
increased.
Keywords :
Vitamin D, Effects, Metabolism, Source.
Vitamin D appears today as a vitamin with a
multiple potentials. It’s involved in many physiological
processes. It was for a long time confined for its role in
phosphocalcic metabolism. Due to its dual food and
endogenous origin, vitamin D constitutes a contributions
and needs remain difficult to define and are currently
under debate. On the other hand, the metabolism of this
vitamin D is better known. Its metabolism involves a first
hepatic hydroxylation leading to the formation of 25-
hydroxyvitamin D 25OHD as well as a renal
hydroxylation resulting in the formation of 1,25(OH)2 D,
the active metabolite of the vitamin D. Vitamin D
deficiency is defined by a serum 25OHD concentration
below 20 ng/mL. On the other hand, the insufficiency in
vitamin D is defined by a concentration between 20 and
30 ng/mL. The deficiency and insufficiency are very
frequent situations associated with an increased risk of
developing various pathologies. The effects of vitamin D
supplementation on reducing the risk of fractures and
falls are documented by various intervention studies. The
other potential extra osseous effects of vitamin D are
mainly documented by observational and experimental
studies. Although there is not yet a consensus on the need
for vitamin D. All experts agree that the recommended
dietary allowance is very insufficient and should be
increased.
Keywords :
Vitamin D, Effects, Metabolism, Source.
