Why does Optimal Prenatal Powder contain such a high amount of vitamin A in the retinol form?

Vitamin A is a very important nutrient for healthy fetal development. Using only beta carotene requires the body to convert beta carotene into the retinyl form of vitamin A. A significant amount of the population has a polymorphism in the BCMO1 gene which greatly reduces the ability to convert beta carotene to retinyl vitamin A. Thus, a significant amount of the population may be vitamin A deficient if only ingesting beta carotene.

This product contains 750 mcg retinyl palmitate, or preformed vitamin A (as well as 750 mcg beta-carotene, which is not included in the "preformed" category for vitamin A - rather, it is considered a "provitamin" because it can be converted into vitamin A within the body). High amounts of retinyl palmitate have been reported as potential factors in pregnancy issues or birth defects. However, this product does not exceed the established safe daily doses of retinyl palmitate. The tolerable upper limits for preformed vitamin A intake, according to the Food and Nutrition Board, are as follows:

Tolerable Upper Intake Levels (ULs) for Preformed Vitamin A
Age	Male	Female	Pregnancy	Lactation
0–12 months	600 mcg RAE(2,000 IU)	600 mcg RAE(2,000 IU)
1–3 years	600 mcg RAE(2,000 IU)	600 mcg RAE(2,000 IU)
4–8 years	900 mcg RAE(3,000 IU)	900 mcg RAE(3,000 IU)
9–13 years	1,700 mcg RAE(5,667 IU)	1,700 mcg RAE(5,667 IU)
14–18 years	2,800 mcg RAE(9,333 IU)	2,800 mcg RAE(9,333 IU)	2,800 mcg RAE(9,333 IU)	2,800 mcg RAE(9,333 IU)
19+ years	3,000 mcg RAE(10,000 IU)	3,000 mcg RAE(10,000 IU)	3,000 mcg RAE(10,000 IU)	3,000 mcg RAE(10,000 IU)

Vitamin A is an essential nutrient, especially during pregnancy and nursing. As with all supplements, we recommend that you consult with your doctor to determine whether this product will be appropriate for your individual needs. You should also take into account preformed vitamin A sources in your other supplements and in your diet when determining whether the dose of this product will work for you. You can also choose to take less than a full dose if you would rather take less vitamin A.

Source:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9096837/