Written by Chanel Chon, dietetic intern, and reviewed by Christina Wright‑Yee, dietetic internship coordinator, both at Rady Children’s Hospital Orange County.
Why calcium and vitamin D matter for growing kids
Eating a balanced diet rich in grains, protein, fruits, vegetables and dairy is one of the best ways to fuel our bodies with essential nutrients. Each essential nutrient plays a special role, acting as a tool to build strength and overall health. A diet that often lacks a variety of foods could potentially result in a nutrient deficiency. Being deficient in a nutrient means our bodies are missing an important tool that we need to stay healthy and grow.
Calcium and vitamin D are two of the most important nutrients for children, especially when it comes to building strong bones and teeth. Deficiencies in these nutrients can occur for several reasons, including limited food variety, poor absorption, underlying illness or lack of sun exposure. When calcium or vitamin D levels are low, it can impact bone development and overall health, making it especially important for children to get enough of both.
Calcium
Calcium is very important for building strong bones and teeth with proper muscle movement and blood clotting. A child might be deficient in calcium due to prematurity, infections, maternal diabetes, or vitamin D deficiency. Look for signs of dry skin, brittle nails, muscle cramps, tingling in the fingers or toes, or weak teeth to detect a possible calcium deficiency.
How much calcium do we need?
- Age 0-6 months: 200 mg/day
- Age 7-12 months: 260 mg/day
- Age 1-3 years: 700 mg/day
- Age 4-8 years: 1,000 mg/day
- Age 9-13 years: 1,300 mg/day
- Age 14-18 years: 1,300 mg/day
How can we get enough calcium?
Dairy-containing foods such as milk, cheese, and yogurt are common sources of calcium.
- 1 cup of milk = 300 mg
- 1 string cheese = 200 mg
- 1 cup yogurt = 200 mg
Other food sources include fortified soy or almond milk, tofu, cooked spinach, cooked bok choy, canned salmon, and canned sardines. Look for the calcium content on the nutrition label of food products to know how much calcium you are getting.
Vitamin D
A major function of vitamin D is helping with calcium absorption in our bodies. These two nutrients go hand in hand in promoting strong and healthy bones. Children are at risk for vitamin D deficiency when on a vegetarian/vegan diet, have an illness and a weak immune system, have poor absorption, or have limited sun exposure. This deficiency may lead to rickets, a condition of soft and weakened bones in growing children.
How much vitamin D do kids need?
- Children under 12 months: 400 IU/day
- Children 12-24 months: 600 IU/day
- Children 2-18 years: 600 Iu/day
Breastfed infants usually are not supplied with sufficient vitamin D and may require supplementation. Infant formulas, however, are typically fortified with vitamin D and will not require supplementation.
How do we get enough vitamin D?
Vitamin D (infamously called the “Sunshine Vitamin”) can be created in our skin when exposed to sunlight. It is recommended to get 15 minutes of sun exposure daily with exposed arms and no sunscreen. Food sources of vitamin D include fatty fish such as salmon and tuna, fortified dairy products, and other fortified foods such as orange juice, breakfast cereals, and soy milk.
If you feel your child is not getting enough vitamin D, ask your doctor or Registered Dietitian about supplementation. There are two types: vitamin D2 and vitamin D3, which is better absorbed in our bodies. Some multivitamins may also include vitamin D.
How to support your child’s calcium and vitamin D needs?
While it can be challenging to make sure your child eats from all the food groups, keeping an eye on calcium and vitamin D can go a long way in preventing deficiencies that affect bone health. Incorporating foods like milk, yogurt, fish, fortified cereals and plant milks is an easy and fun way to build balanced meals that support strong bones and healthy growth. Pairing nutrient‑rich foods with regular outdoor time can also help ensure your child is getting enough of these two essential nutrients.
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At CHOC, we specialize in providing a full continuum of pediatric nutrition services, including inpatient and outpatient services, depending on our patients’ needs.
