Beta-carotene is not the same thing as Vitamin A. Beta-carotene is derived from plants and is "converted into vitamin A" in the body. Vitamin A is a fat-soluble nutrient found in animal tissues such as fish liver oil.

A normal healthy adult would have to take a least 100,000 IU of vitamin A daily for a period of months in order to display any signs of toxicity (i.e. early signs include fatigue, nausea, vomiting, headache, vertigo (dizziness), blurred vision, muscular incoordination, and loss of body hair). All of these symptoms are reversible when supplementation is stopped.

Beta-carotene does NOT cause any side-effects; however, excessive intake (more than 100,000 IU or 60mg per day) sometimes gives the skin a yellow-orange hue. This is a signal that the body has converted as much beta-carotene to active A as it can, leaving the excess as an orange-yellow pigment. This is completely reversible by just cutting back on the amount of beta-carotene intake.

You want to be sure that you're taking "natural" beta-carotene, not the synthetic kind. Synthetic beta-carotene does not have the antioxidant activity that the natural form does.

Look for phrases like: "from D. salina", "from an algal source", "from a palm source", or "natural beta-carotene" on the label.

Individuals who limit their intake of beta-carotene-containing vegetables (dark green or orange-yellow vegetables) or beta-carotene supplements could be at a higher risk of developing a vitamin A deficiency.

Individuals taking beta-carotene for long periods of time should also supplement with vitamin E, as beta-carotene may reduce vitamin E levels.