Approximately 40 million Americans are lactose intolerant, and a number of them are children. In today's Child Wellness report, determining whether your child has a problem digesting milk.

According to recent studies many teenagers are not taking in enough calcium, and if your child is lactose intolerant, their chances of getting in enough are much less.

Lactose intolerance is a problem with the sugar that is in milk. The problem there is the problem is going to be a problem digesting that sugar," Dr. Manny Cirenza said.

It can affect anyone at any age; minorities are more at risk. Symptoms include abdominal pain, diarrhea and gas, abdominal bloating and nausea. Milk is the most common cause but cheese and some yogurts can also contribute to discomfort. Treatment comes in forms of a lactaid enzyme.

"There are many commercially available products such as lactaid milk and over the counter lactaid enzymes you can take just prior to a meal that is high in milk or dairy and can digest the meal appropriately," said Cirenza.

Cirenza says many kids over time will improve. The key is to read labels and look for hidden lactose.

"Breads, cereals, use for backing making pancakes can have these type of things in it lunch meat salad dressing can have the lactose sugar in it," Cirenza said.

Many teenagers are picky eaters and if you have a daughter who is on a diet chances are, they are not going to get in enough calcium. The big question is can kids be on calcium supplements?

The answer is, they can take supplements but only if they aren't getting in enough in the food they eat.

"There are some calcium rich foods, some of your green leafy veggies can be helpful there and sometimes I supplement some of these children and some over the counter you can use a Tums tablet which is a calcium bicarbonate," said Cirenza

According to the RDA, the amount of calcium your child needs each day is as follows. Infants and children up to six months need 210 mg each day. From Age seven months to one year, 270-mg. Children age 1 to 3 years need 500 mg. From Age four to eight years, 800 mg. In addition, for boy girls and boys ages nine to 18 years: both require 1300 mg of calcium each day. Great sources of non-dairy, calcium rich foods include almonds, soy products or rice milk.