Our read is that taking vitamin A is well supported, particularly through whole food sources, given its essential roles in numerous bodily functions.
✓WELLSUPPORTED
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High-risk intervention — consult a physician before acting.Drug-drug interactions, dose-dependence, and screening contraindications apply.
Consensus
89%
broad agreement
Evidence quality
85/100
strong base
Risk
High
specialist only
Cost / month
$
estimated
Effort
Low
time & habit
Abstract
Our read is that vitamin A is considered essential for various physiological processes, including vision, immune function, skin health, and hormone regulation.
Experts suggest that subclinical vitamin A deficiency may be widespread due to low consumption of bioavailable forms, predominantly found in animal foods.
However, caution is advised regarding supplementation, as excessive intake, especially from synthetic sources, can lead to toxicity and potential adverse effects.
Method
To meet vitamin A needs, Paul Saladino suggests consuming organ meats like liver and egg yolks, noting that a few grams of liver provide the RDA compared to over a pound of sweet potatoes. He also recommends obtaining vitamin A from sun exposure and whole foods rather than supplementation.
Evidence detail
01Paul Saladino states that vitamin A, B12, B6, Iron, Zinc, and Selenium are common nutrient deficiencies in the U.S.
02Paul Saladino notes that retinol, a bioavailable form of vitamin A, is essential for activating copper pumps and regulating iron.
03Paul Saladino highlights that consuming over a pound of sweet potatoes daily is needed to meet the RDA for vitamin A, compared to a few grams of liver.
04Andrew Huberman indicates that vitamin A is essential for the phototransduction cascade.
05Paul Saladino claims that declining hormones in men and women can be caused by inadequate intake of specific nutrients and insufficient sunlight exposure.
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06Paul Saladino reports that supplementing with retinol and iron in boys with delayed puberty can induce puberty as effectively as testosterone replacement therapy.
07Paul Saladino states that vitamin A is predominantly found in animal foods in its most bioavailable form, and subclinical vitamin A deficiency is likely widespread due to low consumption of organ meats and inefficient conversion of beta-carotene.
08Paul Saladino suggests that a robust immune system supported by dietary choices including amino acids, proteins, vitamin A, K2, and B12 can reduce coronavirus risk.
09Paul Saladino identifies liver and egg yolks as excellent sources of vitamin A for carnivore diets.
10Paul Saladino notes that vitamin A, C, D, E, selenium, zinc, and copper, often sourced from animals, are essential for a healthy immune system.
11Andrew Huberman mentions that the biological pathway of retinoic acid is similar to the natural pathway where photopigments in the eye convert light.
12David Sinclair states that retinoids inhibit matrix metalloproteinases and promote keratinocyte growth, benefiting skin, hair, and nails.
13David Sinclair suggests that retinoic acid (tretinoin) applied to thinning hair can slow hair loss and promote the Anagen phase, especially with minoxidil.
14Peter Attia notes that acute promyelocytic leukemia (APL) is caused by a maturation arrest treatable with trans-retinoic acid.
Caveats
Our read is that while vitamin A is crucial, there are significant concerns regarding its intake. Peter Attia warns that attempting to accelerate the enzymatic conversion of retinol to retinoic acid can lead to dermatitis. Paul Saladino cautions that excessive intake of liver, particularly with synthetic vitamin A, can lead to toxicity, and that obtaining most vitamin A from plant sources is difficult and potentially problematic due to beta-carotene breakdown products inhibiting vitamin A. He also notes that synthetic antioxidants like beta-carotene, vitamin E, and vitamin C can increase cancer risk and mortality, especially in smokers. David Sinclair points out that retinol use can lead to dry skin, increased susceptibility to sunlight, and irritation. Rhonda Patrick advises individuals at high risk for lung cancer to avoid high doses of vitamin A supplementation as it can accelerate carcinogenesis. Andrew Huberman states that over-the-counter retinols often lose efficacy within one year, making prescription retinoids the only truly effective option, and that the original AREDS formula containing beta-carotene was associated with a slightly increased cancer risk, particularly in smokers. Both Andrew Huberman and Paul Saladino agree that vitamin A overdose is more common from supplements than from food. Rhonda Patrick also expresses concern about excess vitamin A intake from cod liver oil. Paul Saladino suggests that vitamin A and Vitamin D should be obtained from sun exposure and whole foods rather than supplementation, and that esterified propoxylated glycerol (EPG) can reduce the absorption of fat-soluble vitamins like vitamin K and vitamin A. He also mentions that meat-based carnivore diets may lead to insufficient vitamin A and folate intake.
What would change this verdict
Our read is that the verdict would change if new evidence emerged demonstrating that vitamin A from whole food sources consistently leads to adverse health outcomes at typical consumption levels, or if studies showed that the benefits attributed to vitamin A could be achieved more safely and effectively through alternative means without the associated risks of toxicity or side effects. Additionally, if research clarified that the conversion of beta-carotene to vitamin A is consistently efficient across all populations, it could alter the emphasis on animal-derived sources.