Vitamin A (Retinol)
Overview
Vitamin A is a fat-soluble vitamin essential for vision, immune function, and cell growth. It exists as preformed vitamin A (retinol from animal products) and provitamin A (beta-carotene from plants). Adults need 700–900 mcg RAE daily. The upper limit for preformed vitamin A is 3,000 mcg RAE per day. Excess retinol causes liver damage; pregnant women must avoid high-dose supplements. Important: beta-carotene supplements increased lung cancer risk in smokers in clinical trials.
Dosage
0.9 mg · With meal · Take with food
Key Interactions
33 verified interactions found
Beta-carotene from food sources significantly increases circulating retinol levels, improving vitamin A status.
Beta-Carotin wird im Körper zu Vitamin A umgewandelt; kombinierte Einnahme mit Retinol erhöht die Gesamt-Vitamin-A-Zufuhr deutlich. Gesamt-Retinol-Äquivalente aus Supplement und Nahrung auf ≤3mg/Tag begrenzen (BfR 2024).
View details →Vitamin B6 is required for carnosine and other imidazole metabolite synthesis. B6 deficiency reduces carnosine production from beta-alanine and histidine.
Ensure adequate vitamin B6 status if supplementing with beta-alanine for carnosine synthesis.
View details →Zinc is required for Vitamin A mobilization from liver stores and for the synthesis of retinol-binding protein. Zinc deficiency impairs Vitamin A transport and utilization even when Vitamin A stores are adequate.
Ensure adequate zinc status when supplementing Vitamin A. Can be taken together.
View details →Selenium and vitamin A work synergistically to prevent cancer, with both micronutrients enhancing each other's antioxidant and anticarcinogenic effects.
Selen und Vitamin A wirken im antioxidativen System zusammen und können sich gegenseitig beeinflussen. Beide Nährstoffe sollten im normalen Dosierungsbereich bleiben (Vitamin A max. 3.000 µg/Tag, Selen max. 300 µg/Tag).
View details →High-dose retinol can reduce Vitamin D signaling through competition for the RXR co-receptor. However, this competition is dose-dependent and ligand-specific — at normal supplementation doses the interaction is minimal. Only relevant at very high retinol intake (>10,000 IU/day).
Avoid excessive Vitamin A supplementation (>10,000 IU) when taking Vitamin D3. Moderate intake of both is generally safe.
View details →Scientific Sources
- Serum retinol concentrations in children are affected by food sources of beta-ca (1998)
- Daily consumption of Indian spinach (Basella alba) or sweet potatoes has a posit (2004)
- Zinc plus beta-carotene supplementation of pregnant women is superior to beta-ca (2004)
- Short-term (intestinal) and long-term (postintestinal) conversion of beta-carote (2003)
- Double blind, cluster randomised trial of low dose supplementation with vitamin (1999)
- Zink + Vitamin A combination study (PMID:24714829)
- Zink + Vitamin A combination study (PMID:17557517)
- Zink + Vitamin A combination study (PMID:24323003)
- Selenium and cancer: some nutritional aspects. (2000)
- Implications of US Nutrition Facts Label Changes on Micronutrient Density of For (2017)
- Glutathione S-transferase mu genotype, diet, and smoking as determinants of sist (1995)
- A comparative study of blood retinol and selenium in minor lower urinary lesions (1993)
- [Biological effects of selenium]. (1992)
- Source
- Source
- NIH Dietary Supplement Label Database (DSLD)
- PubChem Compound 445354
Frequently Asked Questions
What is Vitamin A (Retinol) used for?
Vitamin A is a fat-soluble vitamin essential for vision, immune function, and cell growth.
What is the recommended dosage for Vitamin A (Retinol)?
0.9 mg. With meal. Take with food.
Does Vitamin A (Retinol) interact with other supplements?
Vitamin A (Retinol) has 33 verified interactions. Top: Beta Carotene, Beta-Alanine.
When is the best time to take Vitamin A (Retinol)?
With meal. Take with food.
Is Vitamin A (Retinol) safe to combine with other supplements?
Always check interactions before combining supplements. Use VitalStack to verify your full stack for free.
Check how Vitamin A (Retinol) fits your full stack
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Check Your Stack →Not medical advice. VitalStack is not a medical device. For personalized health recommendations, consult a healthcare provider.