How much vitamin A per day for hair health?

December 19, 2025 •

3 min read

According to the National Institutes of Health, the Recommended Dietary Allowance (RDA) for vitamin A is 900 mcg RAE for adult males and 700 mcg RAE for adult females. Getting the right amount is crucial, as both deficiency and excess can negatively impact hair health, potentially leading to hair loss.

Quick Summary

This article outlines the optimal daily vitamin A intake to support hair health, discussing its vital role in sebum production and cell growth. It details the risks associated with both insufficient and excessive consumption, and provides a list of healthy food sources for maintaining balanced levels.

Key Points

Balanced Intake is Crucial: Both vitamin A deficiency and toxicity can lead to hair loss, making balanced intake essential for hair health.
Daily Requirements: Adult men need 900 mcg RAE and adult women need 700 mcg RAE of vitamin A daily, which is often met through diet alone.
Toxicity Warning: Do not exceed the Tolerable Upper Intake Level (UL) of 3,000 mcg (10,000 IU) per day for preformed vitamin A, as it can be toxic and cause hair loss.
Food Sources are Safest: Obtain vitamin A from natural food sources like sweet potatoes, carrots, spinach, and eggs to reduce the risk of toxicity.
Supplements Should Be Guided: Only take vitamin A supplements under a doctor's supervision, especially if a deficiency is confirmed by a blood test.
Supports Scalp Health: Vitamin A helps produce sebum, which moisturizes the scalp and prevents dryness and flakiness.
Boosts Cell Growth: As hair is one of the fastest-growing tissues, vitamin A's role in cell growth is vital for strong hair strands.

The Role of Vitamin A in Maintaining Healthy Hair

Vitamin A is a fat-soluble nutrient that plays a critical role in cellular growth, including the rapid multiplication of cells that make up hair. A key function for hair health is the production of sebum, the oily substance secreted by the sebaceous glands to keep the scalp moisturized and the hair shiny and lubricated. Without sufficient vitamin A, the scalp can become dry and flaky, and hair can become brittle and prone to breakage. Conversely, excessive vitamin A can also disrupt the hair growth cycle and cause hair loss.

Recommended Daily Allowances for Vitamin A

The amount of vitamin A required daily varies by age, sex, and life stage. Most people can meet their needs through a balanced diet, making supplementation often unnecessary.

Recommended Dietary Allowances (RDA) for Adults:

Adult Men: 900 mcg RAE
Adult Women: 700 mcg RAE
Pregnant Women: 770 mcg RAE
Breastfeeding Women: 1,300 mcg RAE

The Dangers of Too Much Vitamin A

Since vitamin A is fat-soluble, the body stores excess amounts, which can lead to toxicity, or hypervitaminosis A. This is most commonly caused by over-supplementation rather than food intake. The Tolerable Upper Intake Level (UL) for adults is 3,000 mcg RAE (10,000 IU) per day for preformed vitamin A. Exceeding this limit consistently can cause various adverse effects, including hair loss. This is believed to occur because high levels can disrupt the hair growth cycle, pushing follicles into the shedding phase prematurely. Symptoms of chronic vitamin A toxicity can include dry skin, headaches, blurred vision, and liver problems.

Comparing Vitamin A from Food vs. Supplements

Most healthy individuals should prioritize obtaining vitamin A through their diet rather than supplements. This approach reduces the risk of toxicity and ensures a balanced nutrient intake.


Feature	Food-Based Vitamin A (Beta-Carotene)	Supplement-Based Vitamin A (Retinol)
Toxicity Risk	Extremely low risk, as the body only converts what it needs.	Higher risk of toxicity (hypervitaminosis A) with excessive intake.
Form	Provitamin A carotenoids, converted by the body.	Preformed vitamin A (retinol).
Primary Sources	Sweet potatoes, carrots, spinach, kale, mangoes.	Animal-based sources (liver, eggs) and fortified foods.
Hair Impact	Supports natural hair growth and overall scalp health.	Can cause hair loss if taken in excess of the recommended daily amount.

Excellent Food Sources of Vitamin A

Vegetables: Sweet potatoes, carrots, pumpkin, spinach, kale, red bell peppers.
Fruits: Mango, cantaloupe, dried apricots.
Animal Products: Beef liver, eggs, milk, cheese, yogurt.
Other: Fortified cereals.

When to Consider Supplements

Supplements should generally only be used under the guidance of a healthcare provider. Certain individuals, such as those with malabsorption disorders like Crohn's or celiac disease, or those with specific health conditions, may require supplementation. It's vital to get a proper blood test to confirm a deficiency before starting a supplement regimen.

Conclusion: The Importance of Balance

For optimal hair health, maintaining a balanced intake of vitamin A is key. Most people can achieve this by consuming a diet rich in fruits, vegetables, and animal products. The body efficiently converts beta-carotene from plant sources, offering a safer way to ensure adequate levels. Over-supplementation, especially with preformed vitamin A, carries a significant risk of toxicity and hair loss. Always consult a medical professional before starting any new supplement to ensure it's appropriate for your individual needs. By focusing on whole food sources, you can support healthy hair growth without risking the damaging effects of too much vitamin A.

For more information on the intricate relationship between nutrition and hair health, you can visit the National Institutes of Health website at https://ods.od.nih.gov/factsheets/VitaminA-Consumer/.

Frequently Asked Questions

Yes, excessive intake of vitamin A, particularly through supplements, can cause hair loss. This condition is known as hypervitaminosis A and disrupts the natural hair growth cycle.

A vitamin A deficiency can lead to dry, brittle hair and a flaky scalp. This is because it reduces the production of sebum, the natural oil that moisturizes the scalp.

For most people, a standard multi-vitamin providing the RDA is safe. However, avoid high-dose supplements unless instructed by a doctor, and prioritize getting vitamin A from food sources.

Hair loss caused by vitamin A toxicity is often temporary and reversible. Once the high intake is stopped, it can take 3 to 9 months for hair growth to return to normal.

Vitamin A from plants is in the form of provitamin A carotenoids, like beta-carotene, which the body converts only as needed. Animal sources contain preformed vitamin A (retinol), which can build up to toxic levels if over-consumed.

Topical vitamin A derivatives, like retinoids, are primarily used for scalp conditions and skin health, not direct hair growth stimulation. Using too much can cause irritation.

If you suspect a deficiency or are experiencing hair loss and are concerned about your vitamin A intake, consulting a doctor for a blood test is a prudent step before starting supplementation.