Learn all about Vitamin A
What is Vitamin A?
Strengthen vision & immune defense with essential vitamin A. Supports skin health & cellular communication for total wellness. See the difference!
Benefits of Vitamin A
- Maintains healthy vision by forming retinal pigments essential for both low-light and colour vision[ref]
- Supports immune function by maintaining health of linings in the nose, gut, etc. and promoting proper how immune cells grow[ref]
- Promotes skin health through regulating cell growth, differentiation, and sebum production[ref]
"Vitamin A represents one of the most fascinating nutrients in human health due to its dual role as both a protective agent and developmental signal. Its ability to maintain epithelial barriers whilst simultaneously directing cellular differentiation explains why adequate vitamin A status is crucial for both immediate immune defence and long-term developmental health. The challenge lies in achieving balance - too little compromises multiple systems, while excessive preformed vitamin A can accumulate to toxic levels."
- Dr A. Catherine Ross, PhD, Professor of Nutrition and Physiology, Pennsylvania State University (source)
How to use Vitamin A
Dosage
Men: 900mcg RAE daily; Women: 700mcg RAE daily (Retinol Activity Equivalents)
Timing
Best absorbed with dietary fat; can be taken with meals containing some fat
Notes
Preformed vitamin A (retinol) is more readily absorbed than plant-based carotenoids; conversion rates from beta-carotene vary considerably between individuals
Who should take Vitamin A?
- Individuals with poor night vision or eye health concerns
- Those with compromised immune function or frequent infections
- People with skin conditions including acne or hyperkeratosis (a skin condition causing thickening)
- Pregnant women (with medical supervision for appropriate dosage)
- Individuals with limited access to vitamin A-rich foods
- Those with conditions where fat isn't absorbed well
How does Vitamin A work?
Vitamin A functions through two primary mechanisms: supporting vision and regulating gene expression. In the retina, vitamin A combines with the protein opsin to form rhodopsin, essential for detecting light changes and colour vision. In the rest of the body, its active form (retinoic acid) acts like a hormone, controlling hundreds of genes related to cell growth, immune function, and tissue development by attaching to special receptors inside cells. This gene-controlling action explains vitamin A's widespread effects on epithelial barriers, immune cell function, and developmental processes.
Frequently asked questions
Natural sources of Vitamin A
Preformed vitamin A (retinol) occurs exclusively in animal products, with liver being the richest source (particularly beef, chicken, and fish liver). Other sources include eggs, whole milk, butter, and cheese. Provitamin A carotenoids, which the body converts to vitamin A, are abundant in orange and yellow vegetables (carrots, sweet potatoes, pumpkin), dark leafy greens (spinach, kale), and some fruits (mangoes, apricots). How well it's absorbed and converted vary significantly between sources and individual metabolism.
Potential side effects & risks
Warnings
Pregnant women should strictly avoid high doses of preformed vitamin A (>3,000mcg RAE daily) due to potential risk of birth defects. Those with liver disease should exercise caution with supplemental vitamin A. Long-term supplementation should be monitored by healthcare providers. Smokers should avoid high-dose beta-carotene supplements due to increased lung cancer risk.
Side effects
Preformed vitamin A (retinol) can accumulate in the body. Acute high doses may cause nausea, headache, and vertigo. Chronic excessive intake can lead to hair loss, dry skin, bone pain, and liver damage. Beta-carotene at high doses may cause temporary skin yellowing but is not associated with toxicity.
Interactions
May interact with certain medications including retinoids used for acne treatment, creating additive effects. Can affect the efficacy or toxicity of anticoagulants, drugs potentially harmful to the liver, and tetracycline antibiotics. Mineral oil and cholesterol-lowering medications may reduce vitamin A absorption.