Vitamin A (Beta Carotene): benefits and where to find it ?

Vitamin A or retinol is an essential vitamin for visual health. It is also found in the form of provitamin A or beta-carotene. Discover the role of this vitamin, its recommended nutritional contributions, the risks of deficiency or overdose as well as its medical applications.

Summary

Description of vitamin A and beta-carotene

What are vitamin A and beta-carotene used for?

Where to find it in food ?

Recommended Intakes

The risks of excess vitamin A

Description of vitamin A and beta-carotene

Vitamin A, or retinol, is one of the fat soluble vitamins. It is found in foods of animal origin directly as retinol. It can also be ingested in the form of carotenoids, mainly beta-carotene or provitamin A. These precursors of vitamin A are present in plants. However, not all beta-carotene consumed is converted to retinol. Therefore, in order to obtain equivalent vitamin activity, you need 6 times more beta-carotene than retinol1.

What are vitamin A and beta-carotene used for?

Vitamin A is essential for vision, involved in triggering nerve impulses to the optic nerves. It is essential for growth, since it is involved in cell differentiation. It also stimulates cell renewal and is therefore important for the skin and all mucous membranes. It contributes to the functioning of the immune system. Beta-carotene, meanwhile, has an antioxidant action: in synergy with other micro-nutrients (vitamins C and E, selenium, etc.), it helps protect the body from premature aging1.

Good to know: Vitamin A or retinol and beta-carotene are not very sensitive to cooking. They can, on the other hand, be degraded by oxidation, hence the benefit of keeping foods cool, protected from air and light.

Vitamin A beta Carotene in food

Concentrations of preformed vitamin A are highest in liver and fish oils. Other sources of preformed vitamin A are milk and eggs, which also include some provitamin A. Most dietary provitamin A comes from leafy green vegetables, orange and yellow vegetables, tomato products, fruits, and some vegetable oils . The top food sources of vitamin A in the U.S. diet include dairy products, liver, fish, and fortified cereals; the top sources of provitamin A include carrots, broccoli, cantaloupe, and squash.

Recommended Beta carotene Intakes

Intake recommendations for vitamin A and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies (formerly National Academy of Sciences).


Age	Male	Female	Pregnancy	Lactation
0–6 months*	400 mcg RAE	400 mcg RAE
7–12 months*	500 mcg RAE	500 mcg RAE
1–3 years	300 mcg RAE	300 mcg RAE
4–8 years	400 mcg RAE	400 mcg RAE
9–13 years	600 mcg RAE	600 mcg RAE
14–18 years	900 mcg RAE	700 mcg RAE	750 mcg RAE	1,200 mcg RAE
19–50 years	900 mcg RAE	700 mcg RAE	770 mcg RAE	1,300 mcg RAE
51+ years	900 mcg RAE	700 mcg RAE

*Adequate Intake (AI), equivalent to the mean intake of vitamin A in healthy, breastfed infants.( source https://ods.od.nih.gov/)

The risks of excess vitamin A

After ingestion, retinol is stored in the liver. The excess can come from prolonged intake of food supplements that contain it or from regular consumption of foods that are rich in it (livers, cod liver oil). It can also be linked to liver or kidney disease.

Excess retinol during pregnancy can cause a fetal malformation.

In children, it can be the cause of abnormal thickening of the bones.

In both children and adults, it can lead to digestive disorders (nausea, vomiting, diarrhea), skin signs (dry and itchy skin), as well as hepatomegaly (large liver) 10.