Vitamin A

What is it?

There are two types of vitamin A that are found in the diet.

  • Preformed vitamin A is found in animal products such as meat, fish, poultry and dairy foods.
  • Pro-vitamin A is found in plant-based foods such as fruits and vegetables. The most common type of pro-vitamin A is beta-carotene.

Vitamin A is also available in dietary supplements, usually in the form of retinyl (retinol) acetate or retinyl palmitate (preformed vitamin A), beta-carotene (provitamin A), or a combination of preformed and provitamin A.  Most multi-vitamins contain Vitamin A.[1]

What it does

Vitamin A is necessary for proper vision, resistance to infectious diseases, epithelial cell integrity, bone remodelling and sperm reproduction.  Vitamin A deficiency usually results from malnutrition, but can also be due to abnormalities in intestinal absorption of retinol or carotenoids. Deficiency is prevalent in humans, especially children in certain underdeveloped countries.[2]

Food Sources

Vitamin A can be found in liver (beef, pork, chicken, turkey, fish), carrots, broccoli leaves, sweet potatoes, kale, butter, spinach, pumpkin, collard greens, cantaloupe, eggs, apricot, mango and winter squash.[3]

Recommended Dietary Allowance (RDA)

Canada’s RDA can be found here.

Molecular Dosage Range

Your health care provider may recommend a dose that is somewhat higher than the RDAs; sometimes much higher amounts during certain illnesses. Vitamin A is known as the anti-infective vitamin because it maintains healthy mucous in the respiratory system and thus fights off infection and allergic symptoms.

[1], site reviewed Aug. 23, 2016
[2], site reviewed August, 2016
[3], site reviewed August, 2016