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Summary of Vitamin A
Primary information, health benefits, side effects, usage, and other important details
Vitamin A is not a single compound but a group of chemical compounds that are structurally similar. These compounds include retinol, retinaldehyde, retinoic acid, and provitamin A caretenoids which include beta-carotene, alpha-carotene, gamma-carotene and cryptoxanthin. Retinol and beta-carotene are some of the most common forms of vitamin A found in food and supplements, with the former being found in animals and the latter in plants.
Vitamin A is involved in the modulation of skin health, vision, the immune system, and gene transcription. Different forms of vitamin A will serve different functions. For example, it is retinoic acid that is involved in gene transcription and the maintenance of skin health; it is retinaldehyde that binds certain proteins to the cones and rods of the eye, allowing the eye to function in low-light environments.
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How to TakeMedical Disclaimer
Recommended dosage, active amounts, other details
For topical application, the form of all-trans retinoic acid (Tretinoin) should be used in a facial cream/lotion containing it in the range of 0.01-0.10%, with the lowest concentration having low side-effects but less efficacy and 0.025-0.05% being the sweet spot. Topical application is once nightly.
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Human Effect Matrix
The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what effects vitamin a has on your body, and how strong these effects are.
|Grade||Level of Evidence [show legend]|
|Robust research conducted with repeated double-blind clinical trials|
|Multiple studies where at least two are double-blind and placebo controlled|
|Single double-blind study or multiple cohort studies|
|Uncontrolled or observational studies only|
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
|Notable||Very High See all 3 studies|
|Minor||Very High See all 3 studies|
|-||- See all 3 studies|
|-||- See all 3 studies|
|-||- See study|
|-||- See study|
|-||- See 2 studies|
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Things to Note
Is a Form Of
Also Known As
retinol, retinal, retinoic acid, tretinoin, beta-carotene
Supplements or foods high in retinol should be consumed carefully due to its fat-soluble nature. It is more difficult to clear fat-soluble compounds from the body than water-soluble compounds. A medical practitioner should be consulted before ingesting high amounts of retinol.
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