Vitamin A is a fat-soluble vitamin essential for several biological functions including vision, immune defence, reproduction, and the maintenance of healthy skin and mucous membranes. It exists in two primary forms in the diet:
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Preformed Vitamin A (retinol, retinal, and retinyl esters) found in animal products such as liver, eggs, and dairy
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Provitamin A carotenoids (including beta-carotene, alpha-carotene, and beta-cryptoxanthin) found in colourful fruits and vegetables
Both forms are ultimately converted by the body into retinol, the active form of vitamin A that supports various physiological processes.
The Nutritional Role of Vitamin A
Vision and Eye Health
One of vitamin A’s most recognized roles is in eye health. When converted to retinal, it combines with a protein called opsin to form rhodopsin, a molecule necessary for colour vision and seeing in low light. It also helps maintain the integrity of the cornea and conjunctiva.
There is growing evidence that carotenoids like beta-carotene and beta-cryptoxanthin may help protect against age-related macular degeneration (AMD), a leading cause of vision loss.
Cell Growth and Tissue Repair
Vitamin A supports cell growth and differentiation, helping to maintain healthy skin, respiratory tract tissues, intestines, and other surfaces. This is especially important for wound healing and tissue regeneration.
Immune Function
Vitamin A plays a key role in the development and function of immune cells, particularly T cells, which are vital for fighting infections. Deficiency in vitamin A can impair the body’s ability to resist pathogens and recover from illness.
How Much Vitamin A Do You Need?
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Men: 900 micrograms (mcg) retinol activity equivalents (RAE) per day
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Women: 700 mcg RAE per day
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Upper Limit: 3,000 mcg RAE per day from supplements or high-dose sources
Sources of Vitamin A
Animal-based (Preformed Vitamin A):
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Liver (beef, chicken, turkey)
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Egg yolks
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Butter
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Whole milk and cheese
Plant-based (Provitamin A carotenoids):
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Carrots
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Sweet potatoes
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Kale and spinach
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Red peppers
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Mangoes
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Pumpkin
Deficiency and Toxicity Risks
Vitamin A deficiency is the leading cause of preventable blindness in children worldwide. It can also result in dry eyes, night blindness, impaired immune function, and growth issues.
Too much vitamin A, particularly from supplements or liver, can lead to hypervitaminosis A, a toxic condition with symptoms such as:
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Nausea and vomiting
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Headaches
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Dizziness
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Liver damage
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Bone thinning
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Jaundice
Pregnant individuals should be particularly cautious, as high doses of preformed vitamin A can cause birth defects.
Vitamin A in Skincare
Vitamin A is one of the most researched and clinically supported ingredients in skincare. When applied topically, it can penetrate the skin and convert into its active forms, helping with:
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Cell turnover
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Collagen production
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Smoother, more even skin tone
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Reduction of fine lines and wrinkles
There are several types of vitamin A derivatives used in skincare:
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Retinoids (e.g. tretinoin, adapalene, isotretinoin – prescription-strength)
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Retinol (commonly used in over-the-counter products)
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Carotenoids (antioxidant protection)
Conditions Retinoids Can Help With
Acne:
Topical retinol can be helpful for mild to moderate acne. For more severe, cystic acne, oral retinoids like isotretinoin (commonly known by the brand name Accutane) may be prescribed.
Psoriasis:
Topical retinoids can regulate excessive skin cell growth and reduce inflammation. They are sometimes used alongside corticosteroids for enhanced results.
Hyperpigmentation and Uneven Skin Tone:
Retinoids help speed up skin renewal, reduce dark spots, and promote a more uniform complexion.
Aging:
By promoting collagen synthesis and increasing skin elasticity, vitamin A derivatives can minimize the appearance of fine lines, wrinkles, and photo-damage.
Important Precautions
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Photosensitivity: Retinoids increase skin sensitivity to UV rays, making sunscreen use essential to prevent further damage.
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Irritation: Redness, peeling, and dryness are common side effects, especially when starting a new product. A slow introduction and proper hydration are key.
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Pregnancy: Oral and high-strength topical retinoids are not safe in pregnancy due to the risk of birth defects.
Vitamin A FAQ
Q: If I take high doses of vitamin A internally, should I avoid topical retinoids?
A: Yes, if you are consuming high levels of preformed vitamin A (especially through supplements), it is important to avoid adding topical retinoids unless under medical supervision to reduce the risk of toxicity.
Q: Does eating foods rich in vitamin A improve your skin more than using it topically?
A: Both approaches offer benefits, but they work differently. Dietary vitamin A supports skin health from within, while topical vitamin A (retinoids) delivers more direct, targeted action to the skin's surface layers.
Q: Can I apply vitamin A-rich foods like carrots directly to my skin instead of using retinoid creams?
A: While some foods have antioxidant properties, applying them to your skin is not the same as using a scientifically formulated vitamin A cream. Retinoid products are designed for skin absorption and efficacy.
In Summary
Vitamin A is a vital nutrient that plays essential roles in overall health and skin integrity. Whether consumed in the form of leafy greens or applied through retinol serums, it can offer significant benefits. However, balance is key. Too little puts your body at risk of deficiency, while too much can be harmful, especially during pregnancy. Always consult a healthcare provider before starting high-dose supplements or prescription-strength skincare.
About the author:
Hi, I’m Abinaa, a fourth-year naturopathic medical student at the Canadian College of Naturopathic Medicine with a deep-rooted passion for natural healing, inspired by my South Asian upbringing. Through this blog, I hope to share my journey, explore topics in holistic health and wellness, and offer simple, thoughtful insights that support a more balanced and mindful way of living.
