Your 14-year-old teen tells you she wants to become vegetarian. What do you do?

Adapt, said Dr. Megan Patrick, who practices family medicine at the UCHealth Steele Street Medical Center in Cherry Creek.

The statistics are hard to find and varied, but a survey of several online sources estimates that about 5 percent of Americans, including teens, are vegetarian. About 1 percent of those are vegan. The majority, about 80 percent, appear to be women.

At one time, teens becoming vegetarians didn’t raise alarms among the medical community, but “as we know more about growth and development, it’s coming to our attention,” she said. “We now know that unless you’re paying attention to what they are eating, they might not be getting the right nutrients.”

The age and motivation for becoming a vegetarian varies widely, but the decision often happens in the teen years, she added.

“Part of it is them wanting to assert their independence, or to develop their own identity,” she suggested. “Some cite health or religious reasons, even environmental reasons, or concern about animal cruelty.” Or maybe it’s just because their friends are doing it.

How do parents typically respond?

“A lot of times, especially if the rest of the family is not vegetarian, the parents think it’s a phase and the child will grow out of it, so they don’t necessarily change what other family members eat,” she said. “So the teen will choose to eat just side dishes or convenience foods, such as pasta and bread. Those things don’t necessarily contain key nutrients that a teen needs.”

And it should not be used as a dieting strategy.

“A major concern is that some teens will use the excuse of becoming vegetarian in order to control weight, so it’s actually an eating disorder. It’s just one thing we need to watch out for,” Patrick said.

The more common danger is posed by the fact that teen-agers are still growing and developing, she said.

If not done properly, a teen can end up with deficiencies in protein, iron, B12, calcium, omega-3 fatty acids, vitamin D and zinc – all necessary for growth and development. And they may not get enough calories, either, she added.

The concerns vary with the type of vegetarianism the teen chooses. Typically, a vegetarian diet eliminates meat, though some choose to eat fish and/or seafood (pescetarians) and some will eat eggs and milk (ovo-lacto vegetarians). A vegan diet eliminates all of these and is the most problematic.

“Type does impact health,” Patrick said. “The vegan is most restrictive, definitely. The lack of dairy products impacts their calcium levels and B12 –only found in animal products – so they need to eat fortified foods or take supplements. If they‘re not eating the right balance, they can be at risk.”

Parents need to make sure their child is getting the right combinations of nutrients, she said.

“Certain amino acids are only found in animal products – and they are the building blocks of protein. So if vegetarians don’t combine different sources of protein, they will miss out on those amino acids needed to regenerate tissue and support metabolism.”

There is an upside to the situation. Becoming a vegetarian can help an overweight teen gain control of their weight and eat a healthier diet.

“We know from research that adolescents who are vegetarian have nearly the same percentile for height and growth, but their BMI (body mass index) can be lower. Overall, it can be healthier. It can lower the risk of diabetes and heart disease on down the road – if it’s done right.”

Parental oversight is important, even essential, Patrick said.

“Parents need to be involved, do the research, and don’t dismiss it as a phase,” she said. “What if that phase lasts longer then you anticipated?”

Everything she has read on the topic “really encourages parents to become educated as to what their child needs.”

There are websites that offer suggestions and advice for feeding teens a healthful vegetarian diet, and the USDA is even developing a new food pyramid that reflects a vegetarian diet.

It’s also a good idea for a parent and teen to seek advice from a dietitian or nutritionist at the start.

“I think that’s a great idea,” she said. “It is a more knowledgeable approach. Everybody’s on the same page.”

Specific Recommendations:

Here are Dr. Patrick’s suggestions for how to fulfill the nutritional needs of a vegetarian teen:

• Eat a combination of protein, carbohydrates and fat.
• Protein should be 10 to 30 percent of total energy intake. Protein sources for vegetarians include tofu, eggs, legumes, beans, peanut butter and nuts. There are nine essential amino acids necessary in the diet, and they are found in animal products, milk products, eggs and soy products. Also combining foods that are low in one amino acid with other foods that are higher in that particular amino acid helps to prevent deficiencies – for example, consuming a grain with legumes.
• Fat should be 25 to 35 percent and include two essential fatty acids (alpha-linolenic acid and linoleum acid). These are building blocks for EPA and DHA, which is necessary for eye and brain health. It is found in flaxseed, walnuts, canola oil and soy products
• Carbohydrate intake should be 45 to 65 percent. Half of that should be whole grains.
• Iron available in vegetarian foods is less absorbable than that in animal products. Supplemental vitamin C helps increase iron absorption. Teas can contain tannin, which lowers absorption. Foods high in iron include enriched breads, fortified cereal, soy products, leafy green vegetables, bulgur and dried fruits. Foods high in vitamin C include citrus fruits, strawberries, broccoli and tomatoes.
• Plant sources of zinc include legumes, whole grains, nuts and wheat germ. Milk also contains zinc. Teens need 9 to 11 mg per day.
• The recommended daily intake for calcium intake in teens is 1,300 mg. Low-fat milk, calcium fortified foods or beverages, kale, spinach, broccoli and bok choy are high in calcium. Calcium supplements may be necessary, especially in vegans.
• Vitamin D is found in a few foods, including milk or soy milk and fatty fishes. Teens need 600 IU daily, in addition to adequate sun exposure, which converts it into the active form. Fifteen minutes per day is sufficient in fair-skinned individuals, more for darker skin tones. There are over-the-counter vitamin D supplements as well. It is important for healthy bones, calcium absorption and phosphate metabolism.
• Vitamin B12 is found only in animal products. Teens need 2.4 mcg daily. Milk, eggs and dairy products, as well as fortified food products that list “cyanocobalamin” list in the ingredients are good sources. Vegans should take a supplement that has at least 6-9mcg of vitamin B12.