As you might expect, this vitamin is effective for treating vitamin A deficiency. However, there is not enough evidence to suggest that it works for most other uses.
(Click Does Vitamin A Work? for more information.)
Because it has been studied quite a bit, good information about vitamin A dosing is available. For some of the less studied uses, the most effective (and safe) doses have not yet been established. Both Recommended Dietary Allowances (RDAs) and Tolerable Upper Intake Levels (UL) have been established for the vitamin.
(Click Vitamin A Dosage for more information.)
Most people do not experience side effects with this vitamin, as long as the maximum dosage is not exceeded. Taking too much, however, can result in significant vitamin A toxicity. Some side effects may include:
- Nausea and vomiting
- Peeling of the skin
- Liver problems
- Birth defects (if taken during pregnancy)
(Click Vitamin A Toxicity to learn more, including potentially serious side effects you should report immediately to your healthcare provider.)
Vitamin A can potentially interact with a few medications (see Vitamin A Drug Interactions).