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Vitamin A

FAT-SOLUBLE

Retinol, Retinal, Retinoic acid, Beta-carotene

Vitamin A is a collective term for a group of structurally related fat-soluble compounds that include retinol, retinal, retinoic acid, and various provitamin A carotenoids such as beta-carotene. It is essential for vision, immune function, and cellular differentiation. The most well-known function is its role in vision — specifically in the process of dark adaptation. Vitamin A also regulates the development and function of various immune cells and maintains epithelial barriers in the skin, respiratory tract, and gastrointestinal tract.

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Key Functions

  • Vision and dark adaptation (rhodopsin synthesis)
  • Immune function and epithelial barrier maintenance
  • Cell growth and differentiation
  • Reproduction and embryonic development
  • Skin health and wound healing

Best Food Sources

Liver and fish oilsEggs and dairy productsCarrots and sweet potatoesSpinach, kale, and leafy greensCantaloupe and apricots

Deficiency: Night Blindness / Xerophthalmia

  • Impaired dark adaptation
  • Night blindness
  • Dry eyes (xerophthalmia)
  • Bitot's spots
  • Corneal ulceration and blindness in severe cases

High-Risk Groups

  • Young children in developing countries
  • Those with fat malabsorption
  • People on restrictive diets

Reviewed for accuracy: Content is based on guidelines from the NIH Office of Dietary Supplements, Harvard T.H. Chan School of Public Health, and peer-reviewed medical literature.

Recommended Daily Amount

Adult Men

900 mcg (3,000 IU)

Adult Women

700 mcg (2,333 IU)

Upper Limit (Tolerable)

3,000 mcg (10,000 IU)

Did You Know?

Vitamin A deficiency remains a leading cause of preventable childhood blindness in developing countries.

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