As for the matter of cost: If you take only a daily multivitamin mainly as a medical insurance policy, it certainly won’t hurt your health  as long as you do not already eat a lot of fortified food. And it could help. But it will require spending some money. And if you take a multivitamin and a few individual vitamins and minerals, it’s even more worth your while to make sure you’re not paying more than you need to.

Here’s how to get the most vitamin for the least money.

USE ONLY WHAT YOU NEED Popping too many vitamin pills is not only a waste of money but can be bad for your health. Talk to your doctor about what added vitamins or minerals you might require; you can ask for a blood test to learn what you might be lacking.

For example, if you don’t get enough vitamin D  many people who live in the northern states or who wear sunscreen everyday are low on this crucial vitamin  then buy just a D supplement. Standard multivitamins will probably not have the levels of D you require (many doctors suggest taking 1,000 to 2,000 international units a day).

If your doctor recommends a specific supplement, like omega-3, ask in what form you should be taking it.

Image A Vitamin Shoppe location in Manhattan. ConsumerLab.com found products sold by vitamin chains tended to be more reliable than drugstore brands. Credit... Chester Higgins Jr./The New York Times

FIND A REPUTABLE SOURCE Vitamins and minerals are commodity items, and every manufacturer has access to the same ingredients. For that reason, researchers and scientists say paying more for a name brand won’t necessarily buy you better vitamins.

“When we measure levels of vitamins in the blood, we find the levels are the same whether the person was taking a generic brand or a name brand,” says Dr. Rimm, who has been studying the effects of vitamins for 20 years.