Multivitamins or Saw palmetto supplement capsules

(© Michelle Lee Photography -

Nutrient deficiencies and nutrition-related chronic diseases continue to be on the rise, mainly because the standard American diet is full of excessive amounts of sugar, fat, and salt. With the typical American diet consisting of ultra-processed food, there is little room for fruits, vegetables, whole grains, and healthy proteins. Despite this, some nutrient deficiencies such as vitamin A, remain uncommon. Additionally, given how vitamin A works in the body, supplementing it can be very harmful.

“Vitamin A” is somewhat of an umbrella term, encompassing different compounds. Beta carotene, an antioxidant found in carrots and sweet potatoes, is commonly referred to as vitamin A when it isn’t. The biologically active form of vitamin A is called retinol.

Beta carotene just converts to retinol in the body, and the efficacy of that conversion varies. Generally speaking, vitamin A helps the body maintain a healthy immune system, good vision, and proper cell growth.

Examples of foods containing vitamin A as retinol:

Examples of foods containing beta carotene, the retinol precursor:

Why are vitamin A supplements so risky?

Vitamin A is a fat-soluble vitamin, meaning that it needs fat to absorb effectively in the body and that your body can store it in tissue to use when necessary. Vitamin A deficiencies aren’t that common in the United States, but they are more common in developing nations.

The current Recommended Dietary Allowance (RDA) suggests getting 700 micrograms of vitamin A for women and 900 for men. The upper limit for adults is 3,000 micrograms per day, which is easily reachable if you eat a balanced and varied diet, on top of supplementation.

Vitamin A
(© courtyardpix –

While a few case studies have documented vitamin A toxicity from eating animal liver (the richest source of vitamin A in the diet), most instances of harmful intake have been linked to supplements. Chronic vitamin A toxicity can be characterized by:

  • Vision disturbances
  • Joint and bone pain
  • Sunlight sensitivity
  • Hair loss
  • Liver damage
  • Jaundice

Acute vitamin A toxicity is even worse, being linked to severe liver damage and even death. To put this into perspective, a raw polar bear’s liver has so much vitamin A that even eating just one ounce can be fatal. I doubt you’d have polar bear liver for dinner, but it’s an example of how quickly vitamin A toxicity can harm the human body.

Most supplements on the market contain retinyl palmitate or retinyl acetate. The dosage is usually 3,000 micrograms, which is the the exact upper limit for adults. Even eating a semi-healthy diet while also taking a vitamin A supplement can easily push you over.

Once vitamin A builds in the body, your body doesn’t have an easy way to get rid of the excess. Beta carotene supplements are not as risky on the other hand, as once the body converts enough of it to retinol, it shuts off conversion. If you are deficient in vitamin A, work with your healthcare professional to figure out the best course of action.

Bottom Line

Vitamin A is a fat-soluble vitamin that is critical for immunity, eye health, reproduction, and more. Both deficiency and excess can cause detriment to overall health, so it’s important to meet the recommended amount without chronically or acutely exceeding that, mainly through supplementation.

Most people in the United States are not deficient in vitamin A. Eating a versatile diet is a safe and effective way to get appropriate amounts of this nutrient.

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About Shyla Cadogan, RD

Shyla Cadogan is a DMV-Based acute care Registered Dietitian. She holds specialized interests in integrative nutrition and communicating nutrition concepts in a nuanced, approachable way.

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1 Comment

  1. Dave says: