Vitamin A is a fat-soluble vitamin that is essential for various physiological functions in horses, including vision, growth, immune response, and cellular differentiation. It is obtained through dietary sources, primarily in the form of beta-carotene from fresh forage, which is converted to vitamin A in the horse's body. Vitamin A is stored in the liver and its levels can be influenced by factors such as diet, age, and health status. Deficiencies or excesses of vitamin A can lead to health issues, affecting vision, skin, and overall growth. This page compiles peer-reviewed research studies and scholarly articles that examine the metabolism, dietary requirements, and health implications of vitamin A in equine nutrition and management.
Peltier MM, Peltier MR, Sharp DC, Ott EA.The objective of this study was to determine whether supplemental beta-carotene would influence reproductive function in mares maintained on spring and summer pastures and to characterize plasma carotene concentrations during the estrous cycle. Carotene concentrations in plasma did not vary with day of estrous cycle (P = 0.7455). Mares receiving every other day injections of beta-carotene (400 mg; n = 4) or saline (10 ml; n = 4) during proestrus/estrus did not differ in plasma estradiol (E(2)) concentrations (P = 0.6313), follicle development (P = 0.8068), or plasma progesterone (P(4)) concent...
Kuhl J, Aurich JE, Wulf M, Hurtienne A, Schweigert FJ, Aurich C.In this study, effects of oral β-carotene supplementation to mares (β-carotene group: 1000 mg/day, n = 15; control group: n = 15) from 2 weeks before foaling until 6 weeks thereafter on concentrations of β-carotene, vitamin A and α-tocopherol in plasma, colostrum and milk and plasma of their foals were determined. In addition, effects on fertility were studied. Beta-carotene concentrations increased in plasma and colostrum of β-carotene-supplemented mares compared to control mares (p < 0.05). In mares of both groups, β-carotene concentrations were higher in colostrum than in milk (p &...
