Sources of Vitamin A: Food vs Supplements

What foods contain Vitamin A?

Foods contain two different forms of Vitamin A: preformed Vitamin A (retinol and reinyl ester) that are found in dairy products, eggs, fish, and meat; and provitamin A carotenoids which includes beta-carotene, alpha-carotene and beta-cryptoxanthin found in plants such as leafy green vegetables (spinach, broccoli, kale, romaine lettuce) and orange and yellow vegetables and fruit (carrots, sweet potatoes, apricots, winter squash and cantaloupe). In general, the more intense the color of the fruit or vegetable, the more beta-carotene it contains. Our body converts the provitamin A carotenoids into Vitamin A.

What about supplements?

Vitamin A is available in both multivitamins and stand-alone vitamin A supplements. As with most supplements, it's better to get your vitamin A through food than in a pill, but it is possible to get it with supplements.

Do be aware of how much vitamin A you're taking, however. According to the National Institutes of Health Office of Dietary Supplements, "Because vitamin A is fat soluble, the body stores excess amounts, primarily in the liver, and these levels can accumulate. Although excess preformed vitamin A can have significant toxicity (known as hypervitaminosis A), large amounts of beta-carotene and other provitamin A carotenoids are not associated with major adverse effects [...] Chronic intakes of excess vitamin A lead to increased intracranial pressure [...] dizziness, nausea, headaches, skin irritation, pain in joints and bones, coma, and even death [...] Although hypervitaminosis A can be due to excessive dietary intakes, the condition is usually a result of consuming too much preformed vitamin A from supplements or therapeutic retinoids [...]. When people consume too much vitamin A, their tissue levels take a long time to fall after they discontinue their intake, and the resulting liver damage is not always reversible."

It’s important to note that taking beta-carotene supplements has been associated with an increased risk of lung cancer and cardiovascular disease in current and former smokers. Eating foods containing beta-carotene are not associated with any adverse health conditions, although it is possible for skin to turn slightly yellow/orange when large amounts of beta-carotene are consumed. Once you decrease beta-carotene consumption, your skin will go back to its normal color.

Vitamin A can interact with some medications, and medications may have an adverse effect on Vitamin A levels in your body. If you take any of these medications, it’s important to discuss your vitamin A status with your physician and only take supplements if recommended: the weight loss treatments Orlistat (Alli®, Xenical®), psoriasis treatment acitretin (Soriatane®), and bexarotene (Targretin®), used to treat the skin effects of T-cell lymphoma.

Find Vitamin A in Your Food!

  • Excellent food sources of beta-carotene include:
    • One sweet potato: 1403 mcg RAE
    • ½ cup raw carrots: 459 mcg RAE
    • ½ cup boiled spinach: 573 mcg RAE.
  • For optimum Vitamin A resources to keep your immune system strong and healthy, choose 3-4 servings of dark green or orange/yellow fruit and vegetables every day.
  • Whole milk naturally contains Vitamin A. Reduced fat (2%), low-fat (1%) and skim milk must be fortified with Vitamin A to be nutritionally equivalent to whole milk.
  • If you drink a plant-based milk substitute such as soy, almond, rice, oat or hemp milk, read the Nutrition Facts label to be sure it is fortified with Vitamin A.
  • Light decreases the amount of Vitamin A present in milk, which is why milk is sold in opaque or paperboard containers.

Find out more about Vitamin A!

By Lynn Grieger, RDN, CDCES, CPT, CHWC

References:

  1. National Institutes of Health, Office of Dietary Supplements, Vitamin A Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/ updated 2-14-20, accessed 5-22-20
  2. Zhiyi Huang, Yu Liu, et al. Role of Vitamin A in the Immune System. J Clin Med. 2018 Sep; 7(9): 258.
  3. Ross AC. Vitamin A and retinoic acid in T cell-related immunity. Am J Clin Nutr. 2012;96(5):1166S?72S. doi:10.3945/ajcn.112.034637
  4. J.A. Hall et al. Essential role for retinoic acid in the promotion of CD4+ T cell effector responses via retinoic acid receptor alpha. Immunity. 2011 Mar 25; 34(3): 435–447.
  5. Milk Facts. http://www.milkfacts.info/Milk%20Composition/VitaminsMinerals.htm accessed 5-24-20.
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