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It can be hard to keep track of all the good-for-you vitamins and minerals out there and their benefits, especially if you’re not a healthcare professional or nutritionist. I know I sometimes need a refresher—and I’m a wellness editor! But yes, you might know what vitamin C and vitamin D and zinc do, but maybe you’re not quite sure about antioxidants or omega-3s or adaptogens. And that’s okay, understanding the health and wellness world always takes some studying and research.
So today, we’re going to take a look at vitamin A, a powerhouse vitamin with many benefits. “Vitamin A is a fat soluble nutrient which plays key roles in our immunity, eye health, skin health and cellular growth, including maintaining the integrity of our intestinal lining,” says Mary Purdy, MS, RDN, Nutrition Expert & Sustainability Advisor and Educator at Big Bold Health. “While it’s found naturally in foods like egg yolks, fortified dairy, cod liver oil and fish, in what is called ‘pre-formed vitamin A,’ the majority of food sources for most people are the bright orange fruits and vegetables and dark leafy greens which contain plant compounds called ‘carotenoids” which get converted to vitamin A in the body.” Another form of vitamin A that you might be familiar with is retinol, which can be found in animal products.
Jennifer Martin-Biggers, PhD, MS, RDN, VP of scientific affairs and education at Hum Nutrition, adds that vitamin A in the form of retinols are most easily absorbed and stored. “Carotenoids (like beta-carotene) are called ‘provitamins’ because they must be converted to retinol and other similar forms by the body and their conversion (aka absorption) is dependent on different things, like what else is present in the food and how effective a person’s digestive and absorption capacity may be,” she explains. “There are around 40 to 50 carotenoids in our foods, but more than 750 naturally occurring carotenoids in nature.”
HOW MUCH VITAMIN A DO YOU NEED A DAY
Martin-Biggers explains that vitamin A content in foods and supplements is measured in retinol activity equivalents (RAEs)—in general, 12mcg of beta carotene in a food is equivalent to 1mcg of retinol. “In the US, the recommended dietary allowance for vitamin A in adults over 19 years old is 700 mcg RAE for females and 900 mcg RAE for males each day. If you are pregnant or breastfeeding, your needs are increased,” she says.
The good news is most people in the US get enough vitamin A to prevent diseases or conditions that occur from deficient intake, Martin-Biggers adds. But there are some groups of people that can put them at risk for deficiency, that includes having medical conditions that affect the absorption of fats, like celiac disease or inflammatory bowel conditions. One of the most common consequences of the deficiency is eye disease, like night blindness.
In short, if you have a diet full of variety of the good stuff (carrots, cantaloupe, squash, spinach, etc.), you’re probably getting enough. But you’ll want to make sure you’re pairing these foods with healthy fats. “Additionally it’s important to note that vitamin A is a fat-soluble vitamin, so it’s necessary to consume food sources with some kind of fat in order to facilitate optimal absorption,” Purdy says. “Eating raw carrots or a lovely spinach salad alone may not provide as high of a dosage as combining those foods with a fat source like olive oil or nuts. Additionally, a growing body of evidence indicates that levels of healthy plant chemicals like carotenoids tend to be higher in produce that has been grown using fewer chemical fertilizers and pesticides. Turns out, the health of the soil can make a big difference on the nutritional quality of our food.”
And Martin-Biggers adds that some forms of carotenoids in foods, like lycopene in tomatoes, are actually easier to absorb if it’s cooked, so prepare your foods with that in mind.
If you do find you need to supplement, you’ll want to discuss your options with your healthcare providere. Purdy says that doses higher than 10,000 IUs (3,000mcgs) of pure vitamin A in supplement form can be toxic to the body.
And there are some groups of people who should be very cautious about taking vitamin A supplements. “Smokers should not take beta carotene supplements as it increased lung cancer risk in a study of long term supplementation,” Martin-Biggers says. “Pregnant women should be aware to not consume too much preformed vitamin A (will be on a facts panel as retinol or retinyl ester/acetate) in the form of 750 mcg RAE per day—especially in the first 60 days after conception. Vitamin A in the form of beta-carotene, however, is okay. Hum Nutrition’s Womb Service contains a mix of vitamin A in the form of retinol acetate and beta carotene in levels that are safe for daily intake during pre- and post-pregnancy.”
When shopping for a supplement, read the labels carefully and look for any certifications that can tell you it’s high-quality vitamin. “In a multivitamin, I recommend looking for 100% daily value for retinol activity equivalents,” Martin-Biggers says. “I also strongly recommend exploring the benefits of vitamin A supplements with carotenoids, like lutein and lycopene. The carotenoids may be listed separately from vitamin A on a facts panel.”