Nutrition Science and Everyday Application - beta v 0.1

VITAMINS IMPORTANT FOR VISION 491
addition, some synthetic forms of vitamin A (Retin-A and Accutane, for example) are used as
acne treatments and should never be used during pregnancy due to the risk of birth defects.
Unlike preformed vitamin A, beta-carotene and other carotenoids do not seem to cause
birth defects or other major toxicity effects in high doses. This is because the body doesn’t
convert beta-carotene to vitamin A if it already has excessive amounts of vitamin A. Because
it doesn’t cause toxicity, beta-carotene is usually used as the source of vitamin A in prenatal
multivitamin supplements.
Beta-carotene that isn’t converted to vitamin A is absorbed intact in the intestine. When
high levels of beta-carotene are consumed in the diet, it can have the unusual effect of
making a person’s skin appear to be yellow or orange. The color change doesn’t seem to
be harmful, and normal skin tone returns once the person stops consuming so much betacarotene.
However, studies have shown that long-term consumption of high-dose betacarotene
supplements have been linked to increased rates of cancer and death, so it’s best
to get beta-carotene from food rather than supplements.
Self-check:
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Attributions:
References:
• Zimmerman, M., & Snow, B. Nutrients Important as Antioxidants. In An Introduction
to Nutrition (v. 1.0). https://2012books.lardbucket.org/books/an-introduction-tonutrition/index.html,
CC BY-NC-SA 3.0
• Lindshield, B. (2018). Kansas State University Human Nutrition (FNDH 400) Flexbook.
NPP eBooks. https://newprairiepress.org/ebooks/19
• 1 Sommer, A. (2008). Vitamin a deficiency and clinical disease: An historical
overview. The Journal of Nutrition, 138(10), 1835–1839. https://doi.org/10.1093/jn/
138.10.1835
• 2 World Health Organization. (n.d.). Micronutrient deficiencies. WHO; World Health