Vitamin A
120+ SupplementsVitamin A, a fat-soluble vitamin, plays an essential role in various physiological functions in the human body. Known for its pivotal role in maintaining vision, promoting immune function, and supporting cellular growth and differentiation, vitamin A is crucial for overall health and well-being.
Supplemental Benefits of vitamin A:
Retinal Function: Vitamin A is a critical component of rhodopsin, a pigment in the retina that absorbs light. Rhodopsin enables vision in low-light conditions, making vitamin A vital for night vision.
Age-Related Macular Degeneration: Some studies suggest that adequate vitamin A intake may help reduce the risk of age-related macular degeneration, a leading cause of vision loss in older adults.
Immune System Support: Vitamin A maintains the integrity and function of epithelial tissues, which line the respiratory, gastrointestinal, and urinary tracts, acting as a barrier against infections.
Immune Response: It plays a role in the production and function of white blood cells, which are essential for fighting off infections.
Skin Health: Acne Treatment: Helps reduce the severity of acne and other skin conditions by promoting healthy cell production and repair.
Antioxidant Properties: Beta-Carotene, a precursor of vitamin A, acts as an antioxidant that protects cells from damage by free radicals.
Forms and dosage:
Retinol: The most active and readily usable form of vitamin A in the body. It is essential for vision, immune function, and cellular growth and differentiation.
Retinyl Esters: These are storage forms of vitamin A (e.g., retinyl palmitate, retinyl acetate) that can be converted into retinol when needed. Retinyl esters are often used in supplements and fortified foods. (Preformed vitamin A supplements typically contain retinol or retinyl esters). The supplements described as “Vitamin A (from animal sources)” is in the form of preformed vitamin A, specifically as retinol or retinyl esters.
Beta-Carotene: A provitamin A carotenoid that is converted into retinol in the body. It is a popular choice for supplements due to its antioxidant properties and safety, as it poses a lower risk of toxicity compared to preformed vitamin A.
Alpha-Carotene and Beta-Cryptoxanthin: These are less common but still effective provitamin A carotenoids found in some supplements.
Daily dose:
Vitamin A (Retinol and Retinyl Esters):
Maximum daily dose long-term is 1000 mcg./ 1000mcg RAE (3300 IU)
Maximum daily dose short-term (1-2 weeks) 3000mcg/3000mcg RAE (10000 IU)
Beta-Carotene:
Maximum daily dose for Beta-carotene is 7500 mcg/ 1250 mcg RAE (25000 IU)
Understanding Retinol Activity Equivalents (RAE): This is a more accurate measure of vitamin A activity in the body compared to older units like International Units (IU). It reflects the amount of vitamin A that can be utilized by the body from different sources.