What is Vitamin A?

Vitamin A is a group of compounds that includes retinol, retinal, and retinoic acid. Retinol is the most active form of vitamin A and is found in animal products such as liver, egg yolks, and dairy products. Retinal is derived from retinol and is found in plant-based foods such as carrots and leafy green vegetables. Vitamin A is a Fat-Soluble vitamin and is a vital micronutrient present widely in a balanced nutritional diet. Vitamin A plays a key role in the correct functioning of multiple physiological functions. Humans can metabolise natural forms of vitamin A into biologically active forms which can be used by the body in a range of biological functions, however, the human body cannot synthesise Vitamin A by itself and is therefore essential that this nutrient is consumed in the diet. Vitamin A is a crucial nutrient that plays a vital role in maintaining good health. It is a fat-soluble vitamin that is essential for proper vision, immune function, and the development of the skin and mucous membranes.

What does Vitamin A do?

Vitamin A has many important functions in the body. It is essential for maintaining healthy vision, particularly in low-light conditions. Vitamin A is also important for the development of the skin and mucous membranes, which act as a barrier against infections. It also helps to boost the immune system, which is crucial in fighting off infections and illnesses.

What foods have Vitamin A?

There are two types of vitamin A: retinoids and carotenoids. Retinoids are found in animal-based foods, while carotenoids are found in plant-based foods. Good sources of retinoids include liver, oily fish, egg yolks, and dairy products such as cheese and butter. Carotenoids are found in yellow and orange fruits and vegetables, such as carrots, sweet potatoes, pumpkin, and apricots. Green leafy vegetables, such as spinach and kale, are also excellent sources of carotenoids.

Recommended Dietary Intake (RDI) of Vitamin A:

The recommended daily intake of vitamin A for adult men is 900 micrograms per day, and for adult women, it is 700 micrograms per day. Pregnant women require slightly more vitamin A, with a recommended intake of 770-800 micrograms per day, while breastfeeding women require 1,300 micrograms per day.

Why is Vitamin A important?

Vitamin A is crucial for maintaining good health. It helps to support healthy vision, immune function, and the development of the skin and mucous membranes. Vitamin A also works as a potent antioxidant in the body and plays a role in cell differentiation, and proliferation and is essential to gene regulation.

Safety of Vitamin A

Vitamin A is a fat-soluble vitamin and as such has the ability to be stored within the body. From dietary sources vitamin A doesn’t pose any risk when taken in the recommended as RDI’s, amounts over this may contribute to risks with toxicity if larger amounts are eaten long term. Vitamin A in supplemental form should only be undertaken with the guidance of your healthcare professional for no longer than 3 months unless specifically monitored by your healthcare professional. Vitamin A is contraindicated in pregnancy and breastfeeding in supplemental forms unless otherwise recommended by your healthcare professional.

References

Carazo, A., Macáková, K., Matoušová, K., Krčmová, L. K., Protti, M., & Mladěnka, P. (2021). Vitamin A Update: Forms, Sources, Kinetics, Detection, Function, Deficiency, Therapeutic Use and Toxicity. Nutrients, 13(5), 1703. https://doi.org/10.3390/nu13051703

McEldrew, E. P., Lopez, M. J., & Milstein, H. (2022). Vitamin A. In StatPearls. StatPearls Publishing. http://www.ncbi.nlm.nih.gov/books/NBK482362/

NHMRC, N. H. and M. R. (2021, April 19). Vitamin A [Text]. https://www.eatforhealth.gov.au/nutrient-reference-values/nutrients/vitamin-a

Sklan, D. (1987). Vitamin A in human nutrition. Progress in Food & Nutrition Science, 11(1), 39–55.