Retinyl palmitate: dosage RDA and effects

Dear Ask The Doctor: I take a multi vitamin for diabetics that contains 5000 IU of Retinyl palmitate. Is Retinyl Palmitate safe to take in a multi vitamin? Is there any dosage limits and any concerns with toxicity? I know that beta carotene is safe but I was unsure if Retinyl palmitate is just as safe. Thanks

Dear Robert: Retinyl palmitate is a pre-formed version of Vitamin A, is a synthetic supplement available in dry or oily form. It can be taken orally or by injection to treat Vitamin A deficiency. Also known as palmitate or retinol palmitate, which is converted to an alcohol in the small intestine when ingested. The American Food and Drug Administration(FDA) has established the Recommended Daily Allowance (RDA) of 5,000 IU for vitamin A.  Overdosing preformed Vitamin A forms such as retinyl palmitate leads to adverse physiological reactions known as: hypervitaminosis A, which can be harmful to liver, bones and skin, causing weakness and brittleness, even leading to fatigue and vomiting. Excessive intake of vitamin A is toxic, at dosages of around 20-25,000 IU daily. Consuming more than 25,000 IU of vitamin A per day (adults) and 10,000 IU per day (children) from either food or supplements or both is known to be toxic.