Q. I worry that people are overdosing on vitamins. They’re putting vitamins everywhere these days, even in bottled water. My medical book (20 years old) says you could go a year without any vitamin A and four months without any vitamin B12 or D. If you keep consuming these vitamins don’t they build up to toxic levels?
A. It is possible to overdose on vitamins if you are taking high-dose supplements or drinking and eating fortified foods and beverages. But we are concerned about a growing epidemic of vitamin D deficiency. Studies demonstrate that many children and adults are low in this crucial nutrient. Vitamin B12 may also be in short supply for older people and those taking acid-suppressing drugs to control heartburn.
