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Vitamin A status involves eye health via two separate functions. Retinal is an essential factor in rod cells and cone cells in the retina responding to light exposure by sending nerve signals to the brain. An early sign of vitamin A deficiency is night blindness. [6] Vitamin A in the form of retinoic acid is essential to normal epithelial cell ...
Vitamin A supplementation of children under five who are at risk of VAD has been found to reduce all‐cause mortality by 12 to 24%. [29] Side effects of vitamin A supplements are rare. Vitamin A toxicity is a rare concern associated with high levels of vitamin A over prolonged periods of time.
Some women may need to take iron, vitamin C, or calcium supplements during pregnancy, but only on the advice of a doctor. In the 1999–2000 National Health and Nutrition Examination Survey , 52% of adults in the United States reported taking at least one dietary supplement in the last month and 35% reported regular use of multivitamin ...
Retinol, also called vitamin A 1, is a fat-soluble vitamin in the vitamin A family that is found in food and used as a dietary supplement. [3] Retinol or other forms of vitamin A are needed for vision, cellular development, maintenance of skin and mucous membranes , immune function and reproductive development. [ 3 ]
Vitamins have diverse biochemical functions. Vitamin A acts as a regulator of cell and tissue growth and differentiation. Vitamin D provides a hormone-like function, regulating mineral metabolism for bones and other organs. The B complex vitamins function as enzyme cofactors (coenzymes) or the precursors for them.
Newborn infants are a special case. Plasma vitamin K is low at birth, even if the mother is supplemented during pregnancy, because the vitamin is not transported across the placenta. Vitamin K deficiency bleeding (VKDB) due to physiologically low vitamin K plasma concentrations is a serious risk for premature and term newborn and young infants.
Dietary β-carotene is a provitamin A compound, converting in the body to retinol (vitamin A). [8] In foods, it has rich content in carrots , pumpkin , spinach , and sweet potato . [ 8 ] It is used as a dietary supplement and may be prescribed to treat erythropoietic protoporphyria , an inherited condition of sunlight sensitivity.
For example, many [citation needed] prescription prenatal vitamins will contain a more bioavailable form of folate, 5-methyltetrahydrofolate (5-MTHF). Doses of folic acid over 1 mg are prescription only. The amount of non-prescription prenatal vitamins needed to achieve this dose may have too much vitamin A and lead to fetal toxicity. [2]