@ZipLine-- You're right that vitamin A is commonly used in the treatment of acne. But please don't take more than the daily recommended dose and take a break from the vitamin every now and then to prevent overdose or toxicity.
Vitamin A overdose is called hypervitaminosis A. This is when the amount of vitamin A in your body starts to have toxic effects. If you're experiencing vitamin A toxicity, you might have nausea, headaches, vision problems, drowsiness, mood changes, hair loss and changes in your skin, hair and scalp. Like the article mentioned, vitamin A overdose will also affect how other vitamins and minerals behave in the body. For example, it may affect the function of calcium causing problems with your bones.