Interactions of vitamin A with other micronutrients (vital substances):
Zinc
Zinc deficiency affects vitamin A metabolism in several ways:
- Decreased synthesis of retinol-binding protein (RBP). RBP is important for the transport of retinol via the bloodstream into tissues.
- Decreased activity of the enzyme necessary to convert the storage form of vitamin A – retinyl palmitate – into retinol.
- Zinc is required for the enzyme that converts retinol into retinal (vitamin A1 aldehyde).
Iron
Vitamin A deficiency can worsen anemia caused by iron deficiency (iron deficiency anemia; anemia).Studies found that vitamin A supplementation has beneficial effects on this form of anemia and improves iron status in children and pregnant women. Combined intake of vitamin A and iron showed better therapeutic success of anemia than either iron or vitamin A alone.