Vitamin A deficiency can be considered a nutritionally acquired immunodeficiency disease. Even children who are only mildly deficient in vitamin A have a higher incidence of respiratory disease and diarrhea and a higher rate of mortality from infectious disease. Vitamin A supplementation has been found to decrease both the severity and incidence of deaths related to diarrhea and measles. The onset of infection reduces blood retinol levels very rapidly. This phenomenon is generally believed to be related to decreased synthesis of retinol binding protein (RBP) by the liver. The RDA for vitamin A (2,300 IU/day for women and 3,000 IU/day for men) is sufficient to support normal gene expression, immune function, and vision. Recommend taking a multivitamin/multimineral supplement that provides no more than 2,500 IU of vitamin A or a supplement that provides 5,000 IU of vitamin A, of which at least 50% comes from beta-carotene. High potency vitamin A supplements should not be used without medical supervision. Vitamin D: Recommends that generally healthy adults take 2,000 IU (50 mcg) of supplemental vitamin D daily. Most multivitamins contain 400 IU of vitamin D, and single ingredient vitamin D supplements are available for additional supplementation. Sun exposure, diet, skin color, and obesity have variable, substantial impact on body vitamin D levels. To adjust for individual differences and ensure adequate body vitamin D status, LPI recommends aiming for a serum 25-hydroxyvitamin D level of at least 80 nmol/L (32 ng/mL). Daily supplementation with 2,000 IU (50 mcg) of vitamin D is especially important for older adults because aging is associated with a reduced capacity to synthesize vitamin D in the skin upon sun exposure. Vitamin D reduces the risk of osteoporosis and other health problems.
Vitamin A for Improved Vision, Improved Immune Support
Vitamin A Prevents Diarrhea, Respiratory Ailments
Vitamin A Support Fights Infectious Diseases
Vitamin D for Stronger Bones, Maintain Bone Calcium
Vitamin D Reduces Risk of Osteoporosis and other health problems
