Easy on the Vitamins
Vitamins and good health are practically synonymous. Be careful with supplements, though. You can go overboard with vitamins, according to Self magazine, with overdose symptoms ranging from hair loss to diarrhea to mental disorientation.
Because of differences in individuals' metabolism, body weight and other factors, one person's overdose may cause no problems for another person. But in general, up to triple the recommended daily allowance is considered safe for most people.
Fat-soluble vitamins, like A and D, are more dangerous in large quantities because they're stored in the body longer and can build up to toxic levels. (An exception is vitamin E, which is used too fast by the body to do any harm.) One Boston dairy, in fact, over-fortified its milk with vitamin D in 1991, and put eight people in the hospital as a result.
Water-soluble vitamins, once thought to be safer because they pass out of the body in urine, are now known to strain the liver and kidneys in large doses. Even the popular supplement vitamin C has been faulted-it boosts iron levels in the blood, which is thought to increase the risk of a heart attack.
Apart from the toxicity of excess buildup, large doses of supplements can also cause nutritional imbalances. Vitamins interact with one another in complex ways. Throwing that interaction out of balance can lead to unpredictable and unhealthy results.