Q: Is it true that a baby’s multivitamin intake should be stopped after age 3 months to prevent vitamin dependency? — Via e-mail

A: We all depend on vitamins — molecules by which our bodies carry out chemical reactions that keep us healthy. Ordinarily the necessary vitamins come from a balanced diet and a little sunshine (five to 15 minutes three times a week) to activate vitamin D.

Some diseases and medications interfere with the absorption and metabolism of vitamins. A few rare hereditary diseases also cause vitamin deficiencies, despite a healthy diet; among the potentially affected vitamins are B6, B12 and D.

Children with these diseases may need to take regular supplements of the deficient vitamin to overcome their body’s inability to absorb or metabolize it.

We have never heard about multivitamins’ causing vitamin dependency. Multivitamin supplements aren’t necessary if a child eats a balanced diet. But many children don’t eat such a diet, especially in the first few years, and multivitamins can help them get the vitamins they need.

During the first year or two, iron and vitamin D are likely to be in short supply. In the first weeks of a baby’s life, we recommend that parents discuss iron and vitamin D supplements with their pediatrician.

Although breast milk is the best source of nutrition for babies, breast-fed infants often don’t get enough vitamin D, nor do babies who take in less than a quart a day of formula, which is usually fortified with vitamin D. The American Academy of Pediatrics recommends that infants take in 400 international units of vitamin D per day. Your pediatrician can guide you to the proper dose for your baby.

Depending on a mother’s diet, breast milk may not contain enough iron, though iron in breast milk is better absorbed than the iron in fortified formula. Your pediatrician can also determine your baby’s need for iron supplements.

Inadequate amounts can cause iron-deficiency anemia. During the first years of life, when the brain is growing faster than at any other time, inadequate iron intake has also been linked to learning disabilities that may only become evident later. Paying attention to nutritional needs from the beginning can make a big difference.

Between about 12 and 36 months, many children struggle to control what they eat and often limit their food intake to a few familiar items that may not contain the nutrients they need.

Many children take time to adjust to new tastes and textures. Often a parent may have to introduce a small amount of the same new food up to 15 times before a child will even try it. The process goes more smoothly if a parent simply places the new food on the plate without comment or pressure. Even gentle cajoling leads to more resistance. If you only offer a tiny taste each time, it will be less overwhelming for the child — and a little easier for you to put up with her refusal.

Multivitamins and regular visits to the pediatrician can reassure parents that a child’s growth is on track. Then parents may be less tempted to wage food battles with their children — which parents will surely lose.

There is no way to make a child eat something against her will. Repeated struggles over food are likely to lead to more struggles and perhaps even more serious eating problems later.

Questions or comments should be addressed to Dr. T. Berry Brazelton and Dr. Joshua Sparrow, care of The New York Times Syndicate, 620 Eighth Ave., 5th Floor, New York, N.Y. 10018. Questions may also be sent by e-mail to:

[email protected]