“Should I give my child a multivitamin?” is one of the most common questions I get asked by moms as a pediatrician.

The question often comes up at well-child visits, as part of a conversation about how to improve picky eating. Vitamins also come up at sick visits, especially when a child seems to be sick all the time with colds and coughs—it’s normal to wonder whether a daily multivitamin might “boost” a child’s immune system to prevent them from missing school.

Are vitamins a quick fix for most healthy kids?

The short answer is no. If your child is eating a variety of foods and is not on a restricted diet, then extra vitamin supplementation is not needed. In most cases a daily vitamin for kids is not necessary. Instead, focus on serving healthy foods most of the time.

Can vitamins hurt a child?

A one-a-day multivitamin for extra insurance won’t do harm (except for the expense). But mega dosing on vitamins—particularly fat-soluble vitamins like A,D, E and K that can build up in the body—can cause toxicity. So more is definitely not always better.

In addition, giving a vitamin supplement is not a pass for your child to then eat unhealthy processed snacks and fast food. The biggest concern with the average child’s diet isn’t the lack of vitamins (even sugary breakfast cereals are fortified with vitamins), but that the typical American diet is low in fiber, fruits and vegetables, and high in added sugar and unhealthy fats.

That said, there are a few nutrients that are often lacking in many children’s diets and could use a boost—ideally through nutrition rather than through taking a vitamin:

Iron

Iron is one of the most common nutrient deficiencies in kids of all ages, but particularly in preemies, breastfed babies, toddlers who drink a lot of milk, growing teens and girls who menstruate. Very low iron can affect neurological development and can lead to iron deficiency anemia, which can cause a child to be pale, low energy and tired, with headache and fatigue.

There are many foods rich in iron, including eggs and meats such as turkey, chicken, liver and fish. Iron is also found in dark green leafy vegetables, legumes, seeds and dried fruits. Here’s an important tip: the type of iron found in plant-based foods (known as non-heme iron) is better absorbed if eaten at the same time as some vitamin C. So serve beans with sliced tomatoes, or even broccoli and bell peppers to dip in hummus.

Vitamin D

Vitamin D is a fat soluble vitamin important for bone growth and development and to prevent a disease called rickets. You may be aware that the body can make vitamin D, however sunlight is needed, so depending on where you live, the amount of sun exposure your child gets, the season and even how much sunscreen your child wears, your kids probably still need to ingest some sources of Vitamin D.

Breastfed babies need additional Vitamin D as it is not as readily absorbed from breastmilk (if you have questions or concerns speak with your pediatrician). For older children, food sources of vitamin D include beef, liver, eggs and fish such as salmon, as well as Vitamin D-fortified foods including cereals, dairy products (such as milk and yogurt) and non-dairy milk (such as soy and almond milk).

Calcium

Calcium is a mineral that’s important for strong bones and teeth, as well as for the functioning of the muscles, heart and nervous system. Dairy products (like cheese, yogurt and milk) as well as non-dairy milks are very good sources of calcium. When serving fortified non-dairy milks, make sure to shake well, as the calcium needs to be dispersed throughout the liquid before pouring—otherwise it settles at the bottom of the container. Other non dairy sources of calcium include seafood, dark green leafy vegetables, tofu, legumes, almonds and dried fruit. Many cereals and breads are fortified with calcium as well.

Looking at your child’s overall diet for the week—rather than just one day—is a helpful way to assess the nutrient value of what they are eating. After keeping a food diary for a week, you may be pleasantly surprised to learn that with added nutritious snacks, your child may be meeting their nutritional requirements. Reach out to your pediatrician if you have concerns about your child’s overall diet. They can evaluate and determine with you if added supplementation is needed.

A version of this post originally appeared on Dr. Jen’s website.