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Sep 02, 2023

What does vitamin A do? Functions and the signs of deficiency

When scientists needed to come up with a naming system for the new vitamins that

When scientists needed to come up with a naming system for the new vitamins that were being isolated, they decided if it was fat-soluble (dissolves in lipid and not water) it would be grouped in "A" vitamins, and if it was water-soluble (dissolves in water) then it would be grouped in "B" vitamins. Vitamin A was the first lipid-soluble vitamin to be named.

Vitamin A can otherwise be known as retinol, retinal or retinoic acid. "Vitamin A in adequate amount will support eye health such as helping your eyes to adjust to dim conditions," says Dr. Pedro R. Rodriguez Guggiari, an internal medicine specialist and Chief of Staff at Banner Del E. Webb Medical Center in Sun City West, Arizona. "It also stimulates the production and activity of white blood cells, takes part in remodeling bone, helps maintain healthy endothelial cells (those lining the body's interior surfaces), and regulates cell growth and division such as those needed for reproduction."

Elise Heeney, a clinical dietitian at Banner Del E. Webb Medical Center says these foods are rich in vitamin A:

Vitamin A deficiency is rare in the United States, but worldwide, it is the leading (preventable) cause of blindness in children. It can also lower the ability to fight off infections. The Mayo Clinic says the most common symptoms of Vitamin A deficiency are anemia and dry eyes.

Both Rodriguez Guggiari and Heeney say that supplements can work (for a vitamin deficiency), but you have to be cautious of aggressive and sometimes inaccurate marketing.

Heeney notes that supplements are not regulated (for safety and effectiveness) by the FDA like other medications. She says, "When choosing a supplement, it's best to look for one that has been through quality testing to ensure the supplement was manufactured properly, contains the ingredients listed on the label, and is free from harmful levels of contaminants."

She adds that there are several independent organizations that provide quality testing of supplements such as ConsumerLab.com, NSF International and U.S. Pharmacopeia.

Ultimately, supplements work best when your healthcare provider has found a deficiency.

Since Vitamin A is lipid-soluble, excess amounts can't be excreted in the urine, and are instead stored in the body, usually in the liver. Rodriguez Guggiari says that this can have toxic effects. Per the Harvard School Of Public Health, symptoms of Vitamin A toxicity include:

If you are thinking of taking a supplement, it would be best to speak with your healthcare provider to help you decide if it's a good option.

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