If the multivitamin has only 100% of the Recommended Dietary Allowances (RDA) for each nutrient in the supplement, it probably won’t hurt you. There are RDA’s for protein, vitamin A, D, E, K, C, B6 and B12, thiamin, riboflavin, niacin, folacin (folic acid), calcium, phosphorus, magnesium, iron, zinc, iodine and selenium. The bottle label should give you the measured amount of each nutrient in each pill and what percent each pill contributes to your RDA.
Your body can absorb around 10 to 15% of the nutrients in a vitamin pill. The rest goes down the toilet as urine. So for every $10.00 you spend on supplements, you could be flushing $8.50 down the toilet. Your money would be better spent on food. The human body prefers to take a food, break it down and take the nutrients it needs. Remember that you are dealing with a cave person’s body. I think you are depending too heavily on the supplement and not giving enough credit to the nutrients in your food.
A vitamin is like an enzyme or catalyst. It assists in a chemical reaction. By themselves, they will help prevent a nutritional deficiency and in persons on very low-calorie diets (less than 1200 calories per day), vitamin supplements provide missing nutrients. Vitamins though are not enough. You need protein, fat, and carbohydrates to build and maintain the human body. If you focus on eating a variety of foods, your requirements of vitamins and minerals will probably be met. Unless your doctor has recommended a specific vitamin for a health problem you have, you may be wasting your money on supplements.