How much is too much?
For an adult over 19 years of age, 4300 International Units (IU) of Vitamin A per day is considered sufficient for the proper functioning of the organism. These are normally ensured by a balanced diet, with little need for supplementation in a healthy person.
In order to overdose on Vitamin A, you would have to consume around double your recommended daily intake. According to government guidelines, the upper threshold to which excess intake of Vitamin A is tolerated by your body is 10,000 IU. Exceeding this threshold over a prolonged period of time will lead to overdosing and Vitamin A toxicity. This can have severe effects for your health.
If you are planning on taking any Vitamin A supplements, it is advised that you speak to your doctor first. It is relatively difficult to overdose on Vitamin A purely by eating the foods in which it is found.
Vitamin A can be ingested (via diet or supplements) in two forms. Retinol is naturally found in liver and dairy, while beta-carotene is naturally found in vegetables such as carrots.
However, as the same study cited above points out, Vitamin A toxicity does not occur from the ingestion of beta-carotene, regardless of the dosage. It is only reported when overdosing on retinol. This can only happen through supplementation, as the doses normally ingested through diet – even in large portions, are far too small to do real harm.
What to do if Vitamin A has caused hair loss
If you believe you’ve lost hair as a result of taking too much Vitamin A, you should reduce your intake. Vitamin A stores in the liver, so your body must use up its reserves before you take any more. If you have been taking a supplement, you may need to stop taking this and get your Vitamin A from food while your body uses up its stores. Once your nutrient levels have evened out, your hair should grow back properly.
If there’s another reason for your hair loss, then too much Vitamin A could make the problem worse. In this case you will need to see your doctor to discuss the root cause of your hair loss and find out what the best course of action is.
How to get a healthy intake of Vitamin A
The best way to avoid taking too much Vitamin A is to get it through food, rather than supplements. Red, yellow, orange and dark green vegetables are all great sources of Vitamin A. You can also get it from eggs, liver, fortified milk and cereals. Eat a healthy, balanced diet and you’ll get all the Vitamin A you need. Plus, your body will be able to process it healthily, rather than storing excess amounts which could lead to serious health complications.