Summary: Vitamins prevent vitamin deficiency diseases which are unusual nowadays in this country. We take this role of vitamins for granted, but this is their true role. In hopes of an easy way to better health, vitamins have been reported to help prevent cancer, cure the common cold, prevent aging, etc. In higher doses, vitamins may have some of these benefits, but these benefits are difficult to scientifically prove. Based purely on what I believe, I have given my children supplements of vitamin C, beta carotene and vitamin E. There is no convincing scientific proof that these vitamins are of benefit in healthy people, other than to prevent vitamin deficiency.
Vitamins prevent vitamin deficiency diseases such as scurvy, rickets, beriberi, pellagra and other uncommon conditions. We take this role of vitamins for granted because dietary deficiency (not getting enough in the diet) of these vitamins is very unlikely in this country. Have you ever heard of anyone with these diseases? Unlikely, since the diet only needs tiny amounts of these vitamins to prevent deficiency disease.
Sailors used to get scurvy when traveling on long sea voyages. The body's chemical reaction to make collagen requires vitamin C in small amounts. Collagen is a strong protein that holds the body together accounting for the strength of skin, muscle, bones, gums, hair, blood vessels, etc. Vitamin C is found mostly in fresh vegetables and fruits. Without refrigeration, fruits and vegetables could not be stored on long voyages. With only starvation amounts of grain and dried meats, their intake of vitamin C was minimal and many sailors developed scurvy with symptoms of fragile skin, bleeding gums, weakness, with death eventually resulting from complications such as internal bleeding or infection. If they had taken dried preserved fruits or if they had not been rationed at starvation levels of other foods, many sailors could have avoided scurvy.
Vitamins are only required in small amounts to prevent vitamin deficiency disease. Many people believe that vitamins have other health benefits. This is largely based on the assumption that if a little bit of vitamin is good, then a lot of this vitamin must be even better. This is not true, but many vitamins appear to have biochemical properties that can have health benefits which are totally unrelated to the vitamin deficiency disease. For example, vitamin C in high doses is hypothesized as being an anti-cancer agent and a cure for the common cold. Vitamin C in small amounts normally prevents scurvy, which is totally unrelated to preventing cancer and curing colds. A common theme is that small doses of the vitamin prevents vitamin deficiency disease while high doses of the vitamin has other health benefits.
It would be really nice if we could just swallow some pills to gain better health. Take one pill to lose weight, another to prevent cancer, another to prevent heart disease, another to prevent colds, another to make you smarter, another to make you stronger, another to prevent acne, another to prevent adult aging, etc. Unfortunately, things in life are rarely this easy. We know that vitamins prevent vitamin deficiency, but we very rarely need to take vitamin pills to prevent these since our diets have nearly all the vitamins that we need to prevent deficiency.
Should my children be taking vitamins? It's not likely that your children will have vitamin deficiency disease on their regular diet alone, but taking a vitamin pill once a day, or every other day, or even once a week is a harmless way to be certain of this. The major point here is that taking extra vitamins is usually harmless, unless extreme amounts are taken.
Vitamin A deficiency causes the light sensing cells in the eye to degenerate resulting in night blindness. As long as vitamin A is taken in small amounts in the diet, night blindness is prevented. If a child has measles, treatment with vitamin A supplements seems to result in fewer complications. Vitamin A supplementation is recommended in some measles patients by the American Academy of Pediatrics. This has little to do with eye problems (as in vitamin A deficiency) and is another example of high doses of a vitamin having a benefit unrelated to preventing vitamin deficiency. This is a narrow indication for a vitamin since most children are not likely to get measles due to routine measles immunizations.
Most of the suspected benefits of taking high dose vitamins are not proven. It may be difficult to prove because a disease such as cancer occurs slowly over long periods of time and this may be very difficult to study in human study volunteers. For the foreseeable future, the benefit of vitamins will not be known with certainty.
What vitamins should my child take? No one knows the answer to this and there is no convincing proof that vitamins are beneficial to healthy people other than preventing vitamin deficiency. Based purely on what I believe (without actual scientific proof), I will tell you what I do for my own children. This only applies to children older than two years. I have my children take a vitamin C pill everyday (250mg or 500mg chewables for younger kids, 500mg or 1000mg pills for older kids) and a multiple vitamin with vitamin E and beta carotene twice a week. It is easier for small kids to take a chewable multiple vitamin twice a week, but older kids who can swallow pills may be better off taking a vitamin E pill and a beta carotene pill twice a week instead of the multiple vitamin. Most chewable multiple vitamins do not contain beta carotene so check the label for one that contains beta carotene.
Vitamin C, beta carotene and vitamin E are reported to have anti-cancer activity. Vitamin C is reported to prevent and help cure a common cold. Antioxidants such as beta carotene and vitamin E are reported to slow down the aging process. Oxygen free radicals may play some type of role in cancer and adult aging. Therefore, it makes some sense that antioxidant drugs, which prevent oxygen free radical formation, might prevent cancer and/or slow down the adult aging process. Vitamin C prevents the chemical transformation of common food preservatives to a cancer causing agent. Therefore, it makes sense that Vitamin C might prevent some forms of cancer. Vitamin C is not toxic. Vitamin E is not toxic in commonly taken supplement doses. Beta carotene is a form of vitamin A. Vitamin A is toxic when taken in large amounts, but beta carotene is much less toxic than vitamin A.
As always, it is a good idea to discuss vitamins with your child's physician.
Selenium is a mineral which is also reported to have antioxidant activity, so this is another supplement that may have an anti-cancer and/or anti-aging effect.
Iron is a mineral necessary for the formation of red blood cells which carry oxygen in the body. Males generally do not need iron supplementation, but menstruating females often need iron supplements to make up for monthly blood loss during menses. Since one of the best sources of dietary iron is beef, pork, chicken, fish and other meats, some vegetarians may benefit from iron supplements also. Don't take too much iron. Excessive iron is clearly toxic. Iron overdose can result in severe illness and death. Even modest iron excesses are reported to put one at a higher risk for cancer. So iron supplements should not be excessive. Either eat a normal diet containing adequate amounts of iron or take a modest iron supplement (such as a multiple vitamin with iron) 2 to 3 times per week. Iron levels and red blood counts (hemoglobin) can be easily checked in the blood. Your doctor can tell you whether you need to take an iron supplement. This is a good example of when taking too much of a vitamin or mineral can be harmful.