Vitamin Side-Effects
Too much of anything can kill you, even vitamins. Vitamin A serves as a poignant example. In the early 1960’s, scientists found that vitamin A boosted immunity and prevented blindness in third world countries. A study in Indonesia showed that vitamin A supplementation prevented up to a whopping 50% of childhood deaths caused by disease. As people began to learn of its benefits, supplementation became common. As use became widespread, scientists discovered vitamin overdose – too much of a good thing.
Excess vitamin A has been shown to occur at a mere 20mg per day. Symptoms include water in the brain (hydrocephalus), vomiting, tiredness, constipation, bone pain, and severe headaches. Dry pale skin also occurs. To prevent it, chemists began looking at vitamin A precursors.
Surprisingly, the human body uses beta-carotene to produce vitamin A, but only when it needs it! Utilizing its “natural intelligence,” the body uses a complex set of enzymatic reactions to ensure that you have plenty of vitamin A courtesy of beta-carotene. The best sources for beta carotene are sweet potatoes, spinach and goji berries.
Micki, 
Cris Coleman, and 
bluenote are discussing.467Toggle Comments
bluenote 1:55 pm on May 12, 2008
My research would indicate our bodies actually need vitamin A (retinyl palmitate)in addition to beta carotene however, a small amount (5-10,000 I.U.) would be plenty. It is helpful to know zinc is the ‘door’ that opens the liver to release excess vitamin A; even 10-15 mg. of zinc would be adequate. It is very important not to take too much of anything but I believe those people who suffered the most were taking very large doses of vitamin A and not using sufficient zinc. Thank you for all the wonderful information you provide!
Cris Coleman 8:13 pm on May 15, 2008
My understanding about the “overdose” of Vitamin A stems from it being of the manufactured kind, rather than from the natural kind. The only problem I’ve heard resulting from an “overdose” of the natural kind has been a yellowing of the skin, which goes away once proper dosage is undertaken.
Micki 11:39 am on May 27, 2008
It is my understanding that ALL the fat soluble nutrients work together, so looking at one without considering the others is basically myopic. Too much D can demineralize bones, but w/magnesium, A, K, and some other trace minerals, D works to put calcium into bones. A needs K and D and E (these are the fat soluble nutrients I am talking about) in balanced amounts to not be toxic, which is the way it tends to be found in nature in animal origins – and with a little sunshine thrown in for good measure. Some folks may not convert beta carotene into A very well or some of us may NEED the animal version of A, so this advice may apply only to some but not all. I personally think it is a good idea to eat plenty of colorful (and beta carotene rich) veggies AND to consume the animal form of A in moderate amounts. Just make sure all supplements are not synthetic and all food is as whole and real as you can find!