What Are the Most Common Nutritional Deficiencies in Teenagers?

Quick Answer: Teenagers have increased nutritional needs during rapid growth, making deficiencies in iron, calcium, vitamin D, zinc, and vitamin B12 common concerns. Skipping meals, restrictive diets, limited food variety, heavy menstrual periods, and intensive sports can increase risk. A balanced children’s meal plan with nutrient-rich foods can help prevent deficiencies. Parents should watch for fatigue, poor concentration, growth changes, or restrictive eating and consult a pediatrician before starting supplements or assuming symptoms are caused by a deficiency.

 

According to the American Academy of Pediatrics (AAP), adolescents commonly fall short of recommended amounts of calcium, iron, zinc, and vitamin D.

The teenage years are a time of rapid growth, physical changes, increased activity, and growing independence. At the same time, many teenagers begin making more of their own food choices. Breakfast may be skipped, lunch may come from a vending machine, and dinner may sometimes be replaced by fast food or a quick snack.

As a board-certified pediatrician who provides adolescent care at Gentle Pediatrics, I understand why nutrition can become challenging during adolescence. Teenagers are busy with school, sports, friends, homework, and other activities. They may also become more interested in dieting, vegetarian or vegan eating, or changing their body shape.

These factors can make it harder for some teenagers to get all the nutrients they need.

In this guide, I will break down common teenage nutritional deficiencies in detail.

Why Are Teenagers at Risk for Nutritional Deficiencies?

Teenagers have increased nutritional needs because their bodies are growing rapidly. Bones are developing, muscle mass is changing, blood volume increases, and hormonal changes are taking place.

At the same time, eating habits can become less consistent.

Some common reasons teenagers may not get enough nutrients include:

• Skipping breakfast or meals
• Eating mostly processed or fast foods
• Avoiding fruits and vegetables
• Drinking sugary beverages instead of nutrient-rich drinks
• Following restrictive diets
• Avoiding dairy products
• Eating a vegetarian or vegan diet without careful planning
• Having heavy menstrual periods
• Participating in intensive sports
• Having a limited appetite
• Experiencing an eating disorder or disordered eating

Micronutrients, which include vitamins and minerals, are needed in relatively small amounts but are important for growth, development, and overall health, as noted by the CDC.

Common Deficiencies in Teenagers

1. Iron Deficiency

Iron deficiency is one of the nutritional concerns I pay particular attention to during adolescence.

Iron helps the body make hemoglobin, a protein in red blood cells that carries oxygen throughout the body. It also supports muscle function and normal growth and development.

Teenage girls can have a higher risk because menstrual blood loss increases their iron needs. Teenagers following vegetarian or vegan diets may also need careful planning. The AAP notes that iron from plant foods is not absorbed as efficiently as iron from animal foods.

For ages 14–18, the recommended daily amount is 12 mg for boys and 15 mg for girls.

Good sources of iron include:

• Lean meat and poultry
• Fish and seafood
• Beans and lentils
• Tofu
• Iron-fortified cereals
• Nuts and seeds
• Dark leafy greens

Pairing plant-based iron sources with foods containing vitamin C, such as oranges, strawberries, tomatoes, or bell peppers, can improve iron absorption.

Signs of iron deficiency may include fatigue, weakness, difficulty concentrating, pale skin, headaches, or reduced exercise tolerance. These symptoms can have many causes, so parents should not assume that a teenager needs an iron supplement without medical advice.

2. Calcium Deficiency

The teenage years are extremely important for bone development. Calcium provides structure to bones and teeth and also plays a role in muscle and nerve function.

Teenagers ages 14–18 need about 1,300 mg of calcium each day.

Yet some teenagers avoid milk and other dairy products. Others replace nutritious meals with foods that provide calories but relatively little calcium.

Good sources include:

• Milk
• Yogurt
• Cheese
• Calcium-fortified plant milks
• Calcium-fortified tofu
• Broccoli
• Kale
• Bok choy
• Canned salmon or sardines with bones

The AAP notes that calcium intake can be particularly low among adolescent girls who avoid dairy products.

3. Vitamin D Deficiency

Vitamin D works closely with calcium to support healthy bones. It also has roles in muscle, nerve, and immune function. Teenagers ages 14–18 need about 600 IU (15 mcg) of vitamin D daily.

Vitamin D can come from certain foods, fortified products, and the body’s production after sun exposure. However, sun exposure is not a simple treatment for deficiency because factors such as skin type, location, season, clothing, and sunscreen use affect vitamin D production. Excessive ultraviolet exposure also increases skin cancer risk.

Food sources include:

• Fatty fish
• Egg yolks
• Fortified milk
• Fortified plant beverages
• Fortified cereals

Vitamin D deficiency is not something I recommend diagnosing based on symptoms alone. If a teenager has risk factors or concerns, their pediatrician can determine whether testing is appropriate.

4. Zinc Deficiency

Zinc is another nutrient that deserves attention during adolescence. It supports growth, immune function, wound healing, and normal development.

Teenagers who eat a very limited diet may not get enough zinc. Plant-based diets can also require careful planning because some plant foods contain compounds that reduce zinc absorption. Teen males aged between 14 and 18 years need 11 mg of zinc per day, while female teens require 9 mg.

Sources include:

• Meat
• Seafood
• Dairy products
• Beans
• Nuts
• Seeds
• Whole grains
• Fortified cereals

5. Vitamin B12 Deficiency

Vitamin B12 helps maintain healthy blood and nerve cells and is needed to make DNA. Teenagers ages 14–18 need about 2.4 mcg per day.

Vitamin B12 is naturally found mainly in animal-based foods, including meat, fish, poultry, eggs, and dairy products. Some fortified cereals and nutritional yeast products also contain B12.

This is particularly important for teenagers following a vegan diet. A carefully planned vegan eating pattern can provide good nutrition, but B12 needs special attention because plant foods do not naturally provide reliable amounts of this vitamin.

What Deficiency Signs Should Parents Look for?

Nutritional deficiencies do not always cause obvious symptoms in the beginning. A teenager may simply seem more tired than usual or have difficulty keeping up with normal activities.

Parents should discuss nutrition with a pediatrician if they notice:

• Persistent tiredness or weakness
• Pale skin
• Frequent headaches
• Poor concentration
• Declining sports performance
• Unexpected weight changes
• Slow or concerning growth
• Significant changes in eating habits
• Very restrictive dieting
• Avoidance of entire food groups
• Heavy menstrual bleeding
• Frequent digestive problems
• Signs of disordered eating

These symptoms can have many possible causes, so they should not automatically be blamed on a vitamin or mineral deficiency.

How Can Parents Improve a Teenager’s Nutrition?

I encourage parents to focus on adding nutritious foods rather than creating a long list of foods their teenager cannot eat.

A practical children’s meal plan for an older child or teenager should include a variety of foods from different food groups.

For example:

• Breakfast: Eggs with whole-grain toast and fruit
• Lunch: Chicken, bean, or tofu wrap with vegetables and yogurt
• Snack: Fruit with peanut butter or a handful of nuts
• Dinner: Fish, chicken, beans, or tofu with vegetables, whole grains, and a calcium-rich food
• Drink: Water throughout the day, with milk or a fortified alternative when appropriate

The exact amount of food a teenager needs depends on age, growth, activity level, and individual health needs. There is no single meal plan that is appropriate for every teenager.

Should Teenagers Take Multivitamins?

Not necessarily.

A balanced diet can provide most of the vitamins and minerals a healthy teenager needs. The AAP recommends getting nutrients from food when possible, while supplements may be appropriate when a specific deficiency, restricted diet, or medical condition creates an increased need.

Parents should also avoid giving teenagers high-dose supplements without discussing them with their pediatrician. More of a nutrient is not always better, and some vitamins and minerals can cause harm when taken in excessive amounts.

Nutrition and Adolescent Care at Gentle Pediatrics

Nutrition is an important part of complete adolescent care.

At Gentle Pediatrics, we discuss eating habits as part of a teenager’s overall health rather than treating nutrition as a separate issue. Growth patterns, physical activity, sleep, mental well-being, school performance, medications, and dietary choices can all provide important information.

If we suspect a nutritional deficiency, we can determine whether dietary changes, laboratory testing, nutritional counseling, or another form of evaluation is appropriate.

Our approach is always to make these conversations comfortable for both teenagers and parents. Adolescents should have the opportunity to ask questions and understand why nutrition matters to their growing bodies.

About Dr. Shahid Hasnain

I am a board-certified pediatrician with more than two decades of experience providing comprehensive care for infants, children, and adolescents. I have been board-certified by the American Board of Pediatrics since 1998.

My medical training includes a Master’s in Public Health specializing in Maternal & Child Health, a pediatric internship at Lincoln Hospital in New York, and a pediatric residency at the University of Tennessee Medical Center in Knoxville, where I served as Chief Resident.

At Gentle Pediatrics,I combine medical expertise with a patient, gentle approach to help families make informed decisions about their children’s health.

Final Thoughts

Teenagers need good nutrition to support rapid growth, healthy bones, brain development, physical activity, and everyday life.

Iron, calcium, vitamin D, zinc, and vitamin B12 are among the nutrients that deserve particular attention during adolescence.

The good news is that nutritional deficiencies can often be prevented or addressed through thoughtful food choices and appropriate medical care.

If you are concerned about your teenager’s eating habits, growth, energy levels, or possible nutritional deficiency, talk to Dr. Hasnain at Gentle Pediatrics. A personalized assessment is much more useful than simply guessing which supplement your child may need.

Schedule a Pediatric Visit

If you have concerns about your teenager’s eating habits, growth, energy levels, or possible nutritional deficiencies, our team at Gentle Pediatrics is here to help.

Gentle Pediatrics proudly serves families throughout:

• Sugar Land
• Richmond
• Rosenberg
• Stafford
• Katy
• Houston

Gentle Pediatrics — Sugar Land, Texas

Contact our office today or fill out the online patient registration form to schedule an appointment.

Frequently Asked Questions

1. What is the most common nutritional deficiency in teenagers?

Iron deficiency is an important nutritional concern during adolescence, particularly among teenagers with limited iron intake and girls who have menstrual blood loss. Calcium, vitamin D, and zinc are also nutrients that adolescents may not get enough of.

2. What are signs that my teenager may have a vitamin deficiency?

Possible signs include persistent fatigue, weakness, poor concentration, changes in exercise performance, pale skin, or changes in growth. However, these symptoms can have many causes and do not prove that a teenager has a nutritional deficiency.

3. Do teenagers need multivitamins?

Not every teenager needs a multivitamin. A varied diet can provide most necessary nutrients. Supplements may be recommended when a teenager has a documented deficiency, restricted diet, or another medical reason.

4. Are vegetarian and vegan diets safe for teenagers?

They can be, provided they are carefully planned. Teenagers following these diets need to pay particular attention to iron, vitamin B12, calcium, vitamin D, zinc, protein, and other nutrients.

5. When should I talk with a pediatrician about my teenager’s nutrition?

Consider talking with your pediatrician if your teenager has significant dietary restrictions, unexplained fatigue, concerning weight changes, poor growth, heavy menstrual periods, symptoms of an eating disorder, or a diet that excludes several important food groups.

This article is for general educational purposes and does not replace personalized medical advice, diagnosis, or treatment. Nutritional needs vary from one teenager to another. If you are concerned about your child’s diet, growth, symptoms, or possible nutritional deficiency, consult a qualified pediatrician or healthcare professional.