Vitamin A Supplements: Top Benefits + Retinol vs. Beta-Carotene

Key Takeaway

Vitamin A supplements can offer powerful benefits for vision, skin, immune function, and overall health, but more is not better. For individuals concerned about vitamin A toxicity, beta-carotene may provide a safe and effective option.

What Is Vitamin A?

Vitamin A is an essential fat-soluble nutrient required for vision, immune defense, skin renewal, reproductive health, and normal growth and development. Because it is stored in the body rather than excreted daily, vitamin A is both powerful and potentially harmful if depending upon the dosage level. 

Long recognized for its role in protecting eyesight, vitamin A has also earned a reputation as a cornerstone nutrient for healthy skin and immune function.¹

Pro Tip: Always take vitamin A supplements with a meal containing fat (like avocado, nuts, or olive oil) to maximize absorption. Taking it on an empty stomach may significantly reduce absorption.

Top Benefits Of Vitamin A Supplements

Vision Protection

Vitamin A is indispensable for visual function. It is required for the formation of rhodopsin, a light-sensitive pigment in the retina that enables night vision. One of the earliest and most characteristic signs of vitamin A deficiency is night blindness, reflecting impaired ability to see in the dark. Adequate vitamin A status also supports retinal integrity and may help slow age-related visual decline.²

Immune System Support

Vitamin A plays a central role in immune defense by maintaining the integrity of mucous membranes lining the respiratory, gastrointestinal, and genitourinary tracts. These tissues serve as the body’s first line of defense against pathogens. Vitamin A also supports antibody production, white blood cell function, and normal immune signaling. Deficiency is associated with increased susceptibility to infections, particularly viral and respiratory illnesses.³

Since vitamin A supports intestinal barrier integrity, it may also help protect against gastrointestinal infections in areas where vitamin A deficiency is common.⁴

Skin Health and Acne Support

Vitamin A regulates skin cell differentiation and turnover, determining whether epithelial cells produce healthy or excessive keratin, an important skin protein. Inadequate vitamin A leads to hyperkeratosis, characterized by dry, rough, and scaly skin. Adequate intake supports balanced oil production, clearer pores, and smoother skin. Too much keratin can plug pores and lead to pimple formation. For this reason, vitamin A (retinol) may offer benefits in maintaining a smooth complexion and in the treatment of keratinization disorders.⁵ In addition, topical retinol preparations are showing great benefits in aging skin, including enhancing skin texture, diminishing fine lines, and increasing the collagen content and thickness of both the epidermal and dermal layers of the skin.⁶

Reproductive Health and Development

Vitamin A is essential for normal growth, cellular differentiation, and reproductive function. It plays a critical role in embryonic development, fertility, and hormone-regulated tissue formation. Both retinol and beta-carotene contribute to reproductive health, although precise dosing is especially important in women of childbearing age (see warning below).⁷

Forms Of Vitamin A: Retinol vs. Beta-Carotene

Vitamin A supplements are available in two biologically distinct forms, and understanding the difference between them is critical for safety and effectiveness.

Preformed Vitamin A (Retinol)

Preformed vitamin A—commonly referred to as retinol—is found in animal-derived foods and supplements. Dietary sources include liver, eggs, butter, fortified dairy products, and cod liver oil. Retinol is highly bioavailable and does not require conversion, making it effective for correcting a deficiency. However, because retinol is stored in the liver, excessive intake can lead to accumulation and toxicity.¹

Provitamin A (Carotenoids/Beta-Carotene)

Provitamin A carotenoids, most notably beta-carotene, are found in plant foods such as carrots, sweet potatoes, spinach, kale, and other deeply pigmented fruits and vegetables. The body converts beta-carotene to retinol only as needed, making this form significantly safer for long-term use. Conversion efficiency varies based on genetics, zinc status, and overall nutritional health, but toxicity does not occur from beta-carotene intake.^1,8

Retinol is potent but carries toxicity risk at high doses, while beta-carotene offers a safer approach for general wellness as long as there is conversion efficiency.

Vitamin A Deficiency

Despite its importance, vitamin A deficiency remains a major global health issue.^9-12 Worldwide, over 500 million people are affected, and it is still the leading cause of preventable blindness in many parts of the world. Each year, up to half a million children become blind due to vitamin A deficiency, and approximately half will die within 12 months of losing their sight.³ While severe deficiency is rare in developed countries, nearly 46% of adults in the United States have inadequate vitamin A intake.⁴

Common signs of vitamin A deficiency include: 

• Dry eyes 
• Poor night vision
• Dry or scaly skin due to hyperkeratosis
• Frequent or recurrent infections

In severe cases, deficiency can progress to xerophthalmia, a serious eye disorder that may result in irreversible blindness.

Safety Warning: Dosage + Toxicity

Because vitamin A is fat-soluble, excessive intake—particularly of preformed retinol—can lead to hypervitaminosis A. Symptoms of vitamin A toxicity include headache, nausea, fatigue, dry skin, hair loss, joint pain, and bone loss. Chronic excess intake poses a greater risk than short-term exposure.¹

The tolerable upper intake level for adults is generally 3,000 mcg retinol activity equivalents (RAE), equivalent to approximately 10,000 IU per day of preformed vitamin A. 

Pregnancy Warning

High doses of preformed vitamin A are teratogenic and have been associated with birth defects. Pregnant women should consult their physician before supplementing with preformed Vitamin A (retinol), as higher dosage levels (e.g., above 5,000 IU daily) can be harmful.⁷

How To Choose The Right Vitamin A Supplement

Cod liver oil provides a natural source of vitamin A along with vitamin D, but requires careful dosing. Retinyl palmitate, commonly found in vitamin A supplements or multivitamins, may be useful at RDA levels, but excessive intake (e.g., greater than 10,000 IU daily) should be avoided, especially in women of childbearing age likely to become pregnant. Beta-carotene is generally the safest option for long-term wellness and immune support, but there are often issues of adequate conversion to retinol due to genetics and nutritional factors.

References:

1. National Institutes of Health. “Vitamin A  and Carotenoids.” Nih.gov, National Institutes of Health, 2023, ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/.
2. Sommer A. Vitamin A deficiency and clinical disease: an historical overview. J Nutr. 2008;138:1835-1839.
3. Reider CA, Chung RY, Devarshi PP, et al. Inadequacy of Immune Health Nutrients: Intakes in US Adults, the 2005-2016 NHANES. Nutrients. 2020;12(6):1735.
4. Zhao T, Liu S, Zhang R, Zhao Z, Yu H, Pu L, Wang L, Han L. Global Burden of Vitamin A Deficiency in 204 Countries and Territories from 1990-2019. Nutrients. 2022 Feb 23;14(5):950.
5. Beckenbach L, Baron JM, Merk HF, Löffler H, Amann PM. Retinoid treatment of skin diseases. Eur J Dermatol. 2015 Sep-Oct;25(5):384-91. 
6. Quan T. Human Skin Aging and the Anti-Aging Properties of Retinol. Biomolecules. 2023 Nov 4;13(11):1614.
7. Azais-Braesco V, Pascal G. Vitamin A in pregnancy: requirements and safety limits. Am J Clin Nutr. 2000;71(Suppl):1325S-1333S.
8. Borel P, Desmarchelier C. Genetic Variations Associated with Vitamin A Status and Vitamin A Bioavailability. Nutrients. 2017 Mar 8;9(3):246.
9. Imdad A, Mayo-Wilson E, Herzer K, et al. Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age. Cochrane Database Syst Rev. 2022;3(3):CD008524.
10. World Health Organization. Vitamin A supplementation in infants and children 6–59 months of age. WHO eLENA. Updated August 9, 2023.
11. World Health Organization. Vitamin A supplementation. Essential Programme on Immunization (EPI) integration page. Accessed 2026-02-02.
12. World Health Organization. Summary of evidence: Vitamin A supplementation in infants and children 6–59 months. WHO guideline evidence summary (NCBI Bookshelf).