Calcium is a mineral your body uses to build and maintain strong bones and teeth. Bones are living tissue, so they are constantly being broken down and rebuilt throughout life. Getting enough calcium during childhood and the teen years is especially important because this is when much of your bone mass is formed.
Strong bones help support movement, protect organs, and lower the risk of fractures later in life.
Vitamin D helps the body absorb calcium from food and use it in bones. Weight-bearing activities, such as walking, running, dancing, and jumping, also signal bones to become stronger. Good calcium sources include milk, yogurt, cheese, fortified plant milks, tofu made with calcium, leafy greens, and canned fish with soft edible bones.
A healthy bone-building routine combines calcium-rich foods, vitamin D, regular physical activity, and safe sunlight exposure when appropriate.
Key Facts
- Calcium helps build the hard mineral structure of bones and teeth.
- Vitamin D helps the small intestine absorb calcium from food.
- Bone remodeling means old bone is broken down and new bone is formed.
- Peak bone mass is the greatest amount of bone tissue a person builds, usually reached in early adulthood.
- Calcium balance depends on intake, absorption, storage in bones, and loss through urine and stool.
- Approximate calcium intake: 1 cup milk or fortified plant milk = about 300 mg calcium.
Vocabulary
- Calcium
- Calcium is a mineral needed for strong bones, teeth, muscle movement, nerve signals, and blood clotting.
- Vitamin D
- Vitamin D is a nutrient that helps the body absorb calcium and supports normal bone growth.
- Bone density
- Bone density is a measure of how much mineral material is packed into a section of bone.
- Compact bone
- Compact bone is the hard outer layer of bone that gives strength and protection.
- Spongy bone
- Spongy bone is the lighter honeycomb-like inner bone tissue that helps absorb forces and reduce weight.
Common Mistakes to Avoid
- Thinking calcium only matters for older adults is wrong because children and teens are actively building the bone mass they will depend on later.
- Forgetting vitamin D is wrong because calcium from food is not absorbed as well when the body does not have enough vitamin D.
- Assuming supplements are always better than food is wrong because calcium-rich foods can also provide protein, phosphorus, and other nutrients that support health.
- Ignoring exercise is wrong because bones respond to weight-bearing activity by becoming stronger, while a calcium-rich diet alone is not the whole plan.
Practice Questions
- 1 A student drinks 2 cups of fortified plant milk, and each cup has 300 mg of calcium. How many milligrams of calcium did the student get?
- 2 A yogurt has 250 mg of calcium and a serving of tofu has 350 mg of calcium. If a student eats both, what total amount of calcium did they consume?
- 3 Explain why a student who eats calcium-rich foods but gets very little vitamin D might still have trouble building strong bones.