Vitamin A

Vitamin A is a group of fat-soluble retinoids, including retinol, retinal, and retinyl esters. Two forms of vitamin A are present in the human diet.

  • Preformed vitamin A (retinol and its esterified form, present in food from animal sources such as dairy products, fish, and meat (especially liver).
  • Provitamin A carotenoids. Provitamin A carotenoid is beta-carotene.

These plant pigments are converted into vitamin A through the human body. Both vitamins from animals and plant sources must be metabolized intracellularly to retinal and retinoic acid, the active forms of vitamin A, to support the vitamin’s essential functions in the human body. 

Vitamin A and night blindness

Consumption of adequate vitamin A reduces the risk of night blindness and may reduce the age-related decline of eyesight.

Lower the risk of specific cancer

Consumption of vitamin A in higher amounts in beta-carotene lowers the risk of many types of cancer, including Hodgkin’s lymphoma and cervical, lung, and bladder cancer.

Healthy immune system

Vitamin A plays a significant role in maintaining the body’s natural defense system. This includes the mucous barriers in your eyes, lungs, gut, and genitals which help trap bacteria and other infectious agents. Vitamin A help in the production and function of white blood cells, which may help capture and protect bacteria and other pathogens in the blood.

Promote healthy growth

Vitamin A plays an essential role in maintaining a healthy reproductive system in both males and females; due to adequate vitamins, average growth and development of embryos are also ensured during pregnancy.

Vitamin A rich food

The best sources of vitamin A are cod liver oil, apricots, bell peppers, grapefruits, orange, and yellow fruits and vegetables, tomatoes, carrots, sweet potato, mangoes, and eggs.  Other sources of beta-carotene such as broccoli, spinach, and most dark green, leafy vegetables.

RDA of vitamin A

The recommended daily allowance for vitamin A is 900 mcg for men and 700 mcg for women.  

Vitamin A rich smoothie 

Ingredients

  • 1 medium ripe banana
  • 3 cups spinach packed
  • 1 cup whole frozen strawberries
  • ¼ cup frozen pineapple chunks
  • 1 cup unsweetened almond milk or milk of choice
  • 1 tablespoon chia seeds

Method

 Add all ingredients spinach, banana, strawberry pineapple, almond milk, and chia seeds. Blend until smooth.

Nutrient profile

  • Calories         286
  • Fat                 8g
  • Carbs             53g
  • Protein           8g
  • Vitamin A      8515%
  • Vitamin C      140%

References

  • Johnson EJ, Russell RM. Beta-Carotene. In: Coates PM, Betz JM, Blackman MR, et al., eds. Encyclopedia of Dietary Supplements. 2nd ed. London and New York: Informa Healthcare; 2010:115-20.
  • Ross CA. Vitamin A. In: Coates PM, Betz JM, Blackman MR, et al., eds. Encyclopedia of Dietary Supplements. 2nd ed. London and New York: Informa Healthcare; 2010:778-91.
  • Ross A. Vitamin A and Carotenoids. In: Shils M, Shike M, Ross A, Caballero B, Cousins R, eds. Modern Nutrition in Health and Disease. 10th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2006:351-75.
  • Solomons NW. Vitamin A. In: Bowman B, Russell R, eds. Present Knowledge in Nutrition. 9th ed. Washington, DC: International Life Sciences Institute; 2006:157-83.
  • Sommer A. Nutritional blindness: xerophthalmia and keratomalacia. New York: Oxford University Press; 1982.