There are two types of people out there: people who have a multivitamin and some vitamin C (probably expired) tucked away in their medicine cabinets, and people who have accumulated so many different vitamin, mineral, and herbal remedy bottles that it looks like they have a problem.
Truth be told, the majority of us aren’t exactly sure what every individual vitamin does—even if we do own a supplement for every letter of the alphabet. We’re going to break down the basic function of the most popular supplements out there—because if you choose to take them, you should know how they work! (Of course, check with your doctor before you begin any supplement regimen.)
This week, we’re starting from the beginning: Vitamin A.
What does it do?
Vitamin A is the fat-soluble vitamin involved in immune function, cell communication, reproduction, and eye health. Because it supports normal functioning of the membranes around the eye and cornea, it’s critical to vision. It also plays a major role in the growth and regeneration of heart, lung, kidney, and skin cells.
Many don’t realize that retinol—the mysterious compound advertised on your night cream—is a form of vitamin A. Synthetic retinoids (similar to retinol in molecular structure) have been used for decades in the cosmetic industry as a smoothing and anti-aging treatment. When someone is deficient in vitamin A, the most obvious symptoms crop up on skin. “Chicken skin” or hyperkeratosis pilaris (dry, raised bumps) found on the backs of arms is one of the first signs of deficiency, and eventually skin all over the body becomes scaly and rough. Because vitamin A is necessary for cell turnover, it’s beneficial for treating lots of skin conditions, from psoriasis to acne. It’s also needed for the production of sebum, the oil that keeps hair and skin moisturized, and one of the positive benefits of increasing vitamin A intake is shinier, healthy looking hair.
Plus, vitamin A doubles as a powerful antioxidant, protecting cells from oxidative and free radical damage.
Forms of vitamin A
There are two forms of vitamin A—pre-formed vitamin A (retinol), which is easy for the body to absorb, and beta-carotene, which the body has a hard time converting into vitamin A and is therefore harder to absorb.
Where to find vitamin A
Retinol can only be derived from animal sources—sorry, vegetarians and vegans out there! Liver, kidney, organ meats, dairy milk, cream, butter, and eggs are all excellent sources. If you’re allergic to dairy and the thought of eating organ meats a few times a week is too much for you, try adding cod liver oil into your diet. It has tons of retinol, as well as vitamin D, another important mineral for skin and cell regeneration. Not sure how to make liver taste good? We’ve got a recipe for you!
Beta-carotene gives fruits and veggies their vibrant colors—carrots, tomatoes, broccoli, and papaya have some of the highest amounts. You’ll also get a healthy dose of it if you’re eating leafy greens, orange and yellow veggies, and brightly colored fruits.
Recommended Dietary Allowance (RDA)
The National Institutes for Health (NIH) suggest different intake levels depending on age and gender. It’s measured in micrograms, but is sometimes listed on nutrition labels as IUs, or international units; one IU is equal to 0.3 mcg of retinol. And here’s where it gets a little confusing: Because beta-carotene must first be converted to vitamin A before the body can use it, you’ll need to eat more to get the daily recommended dosage. One microgram of retinol is equal to 12 micrograms of beta-carotene. Below are the recommended daily intakes based on the NIH’s findings:
0-6 months: 400 mcg/day
7-12 months: 500 mcg/day
1-3 years: 300 mcg/day
4-8 years: 400 mcg/day
9-13 years: 600 mcg/day
14+ years (male): 900 mcg/day
14+ years (female): 700 mcg/day
Do you need to supplement with vitamin A?
Maybe. If you’re a vegan or vegetarian, you might want to consider adding a retinol supplement into your daily routine, because even if you’re eating tons of fruits and veggies, you still might not be getting the RDA for your age and gender.
If you suspect that you have a vitamin A deficiency, it’s best to tell your doctor so he or she can test your blood levels before starting on a supplement regimen. You could also start eating more vitamin A–rich foods, and see if that makes a difference on your symptoms.
Illustration by Foley Wu