Everything You Need to Know About Vitamin A

Jun 16, 2022 | BY First & Foremost Clinical Team

Everything You Need to Know About Vitamin A

Vitamin A is a critical micronutrient necessary for your body to grow and develop properly, helping to guard against illness, and support vision. Understanding how to obtain the recommended daily allowance (RDA) of vitamin A to prevent deficiency or over-supplementation is important, as is understanding the various forms of vitamin A you’ll need, and how they interact with other nutrients. 

First & Foremost is an evidence-based, nutrition supplement program that helps take out the guesswork of when and how to get the right amount and forms of vitamin A. And because vitamin A is easily consumed through food when eating a balanced diet, F&F supplementation contains low-dose vitamin A to complement a healthy lifestyle.

What is vitamin A?

Vitamin A is a group of essential micronutrients that plays a critical role in your immune system, growth and development, and reproductive system. Different forms of vitamin A help you get your daily recommended allowance: preformed vitamin A is found in animal products, supplements and fortified foods in the form of retinol and retinyl esters (called retinoids), while plants provide it in the form of provitamin A carotenoids.  

Carotenoids are a group of more than 700 different types of molecules, which include beta-carotene, lycopene and lutein. Certain carotenoids, such as beta-carotene, are processed by the body into retinol. Retinol is what the body needs for good vision, cellular reproduction, and a healthy immune system.

What is the recommended daily allowance for vitamin A?

The recommended daily amount of vitamin A is 900 mcg for men and 700 mcg for healthy adult women. A woman’s vitamin A requirements increase during pregnancy and nearly double for lactation. For those who are pregnant or trying to get pregnant, 770 mcg is recommended, while women who are breastfeeding need up to 1300 mcg. It’s important not to consume too much vitamin A, though, because acute and chronic toxicity is harmful to your body.

What’s the best way to get vitamin A? 

Because vitamin A comes in different forms, you’ll likely need a balanced diet of colorful fruits and vegetables, as well as certain animal products. Foods high in the provitamin (carotenoid) form of the micronutrient include squash, pumpkin, kale, and oranges. However, most Americans get their vitamin A from the preformed (retinoid) micronutrient found in milk, eggs, fortified foods, or beef liver. 

While vitamin A is easily consumed through food, the bioavailability and absorption of carotenoids can be affected by a number of factors. In fact, the absorption rate of vitamin A from plants can range from below 10% to up to 65%, based on its interactions with other foods, an individual’s genetics, and their unique gut biome.  

When it comes to preformed vitamin A, such as those that come from milk and eggs, absorption is 70% to 90%. In addition to being rich in protein, the typical Western diet provides ample preformed vitamin A. Because vegans abstain from animal products and thus consume mostly the carotenoid form found in fruits and vegetables, they count on their body to convert carotenoids to retinol. Because of the lower absorption rate from plant-based foods, they must either consume foods rich in carotenoids or supplement to ensure enough vitamin A. 

As mentioned previously, genetics play a role in carotenoid absorption. Vegans who rely solely on plant-based foods to convert their beta carotene to retinol may find they have a genetic mutation that can reduce the conversion process, making plant foods an inadequate source of vitamin A. This can result in vitamin A deficiency and necessitate supplementation.  (Carnivores who get enough preformed vitamin A may also have this mutation, but it is less consequential since their vitamin A intake doesn’t rely as heavily on this carotenoid conversion process.)

How does vitamin A react with other nutrients? 

Too much or too little vitamin A can interfere with the positive effects of vitamin D, increasing risk of fracture. Too much vitamin A can also decrease absorption of another fat-soluble micronutrient, vitamin K. 

What happens when you're deficient in vitamin A? 

The myth of eating carrots to improve your vision actually has some truth to it. 

Low levels of vitamin A can negatively affect your vision. Night blindness, or poor vision in dim lighting, is an early symptom of vitamin A deficiency. Over time, blindness can develop. This is because  the photoreceptors in your retina need the retinol form of vitamin A to work properly. A deficiency can also prevent your eyes from becoming dry and damaged, but high doses of retinol over several days can correct the deficiency. 

Other symptoms of vitamin A deficiency include fatigue and an increased risk of infection and infertility. Researchers have also found that low levels of vitamin A can affect hemoglobin production and increase the risk of anemia.

Can you take too much vitamin A? 

Because vitamin A is a fat-soluble vitamin, excess amounts are stored in the body’s fat tissue. Over time, this can build up and result in dangerous side effects. More than 60,000 cases of vitamin A toxicity are reported each year in the United States. (This is why, while we strive for the RDA on most essential nutrients in our formulation, we include a safe, conservative dose of vitamin A to reduce any risk of oversupplementation.)

Overdosing on vitamin A (in dietary or supplement form) can cause nausea, headache, fatigue, and dizziness. If you take excess vitamin A over a long period of time, you may develop dry itchy skin, weight loss, anemia, headache, and enlarged liver and enlarged spleen, and bone and joint pain. However, most people who discontinue the supplement usually see the symptoms gradually decrease and they recover. 

Because of the risks associated with vitamin A, it’s also important not to consume additional vitamin A supplements if you’re already taking medication that provides a synthetic form of vitamin A, such as retinoids. 

While it’s a crucial nutrient for pregnant women and the growing fetus, vitamin A can cause birth defects when excessive amounts are taken during the first two months of pregnancy. About 1-2% of babies who are born to women who ingested over 10,000 IUs of preformed vitamin A daily were born with defects, including cleft lip or palate, cardiac issues, or central nervous system abnormalities. 

How can I get the right amount of vitamin A?

First & Foremost’s dayparted micronutrients provide the right amount of vitamin A — you get the right nutrients at the right time for optimal bioavailability. To reduce the likelihood of vitamin A toxicity, F&F includes a conservative dose that safely bridges the gap between the amount of vitamin A someone receives in their diet and the RDA. F&F also splits the dosage of 95 mcg of beta-carotene (provitamin) and 95 mcg of palmitate (preformed). 

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