Why is Calcium Important for Growth and Overall Health?

November 18, 2025 •

3 min read

Over 99% of the body's calcium is found in the bones and teeth, giving them structure and strength. For this reason, calcium is an essential mineral that is particularly important for growth, development, and overall health, especially during childhood and adolescence. The mineral plays a crucial role in building and maintaining strong bones, but its importance extends far beyond skeletal health to support vital bodily functions.

Quick Summary

Calcium is a mineral essential for building strong bones, regulating muscle function, transmitting nerve signals, and other vital bodily processes. Adequate intake is critical during growth periods to build peak bone mass, which helps prevent osteoporosis later in life.

Key Points

Peak Bone Mass: Maximum bone density is built during childhood and adolescence, a critical period when high calcium intake is essential for establishing strong bones that can help prevent osteoporosis later in life.
Skeletal Structure: Over 99% of the body's calcium resides in the bones and teeth, where it provides structural integrity and hardness.
Muscle Function: Calcium regulates muscle contraction, including the heartbeat, by allowing the necessary interaction between muscle proteins.
Nerve Communication: Calcium is vital for nerve transmission, enabling nerves to send messages between the brain and all other parts of the body.
Vitamin D Synergy: Vitamin D is necessary for the body to properly absorb calcium from food; without it, calcium cannot be used effectively for bone health.
Dietary First Approach: It is best to get calcium from a variety of foods like dairy products, leafy greens, and fortified options, reserving supplements for when dietary intake is insufficient.
Deficiency Consequences: Long-term calcium deficiency can lead to softened or weak bones (rickets in children, osteomalacia and osteoporosis in adults) and other symptoms like fatigue, confusion, and muscle cramps.

The Foundational Role of Calcium in Skeletal Development

Calcium is the most abundant mineral in the human body, with the majority stored in the bones and teeth in the form of hydroxyapatite. During childhood and adolescence, bones grow and strengthen rapidly, making sufficient calcium intake paramount. This period is a unique window for building bone mass, which helps determine adult bone density and reduces the risk of future fractures and conditions like osteoporosis. The mineral acts as a fundamental building block, constantly being deposited and reabsorbed in a process known as bone remodeling. A deficiency during this critical time can hinder growth and lead to lifelong skeletal issues.

More Than Just Bones: Other Critical Functions of Calcium

While its role in bone health is widely known, calcium is also a powerful intracellular messenger, or 'second messenger,' that is critical for regulating a variety of physiological processes. Just the remaining 1% of the body's calcium, circulating in the blood, is responsible for several life-sustaining functions.

Muscle Contraction: Calcium ions are essential for the contraction and relaxation of all muscle types, including skeletal, smooth, and cardiac muscle. A nerve impulse triggers the release of calcium, which enables the proteins actin and myosin to interact, causing the muscle fibers to slide past each other.
Nerve Transmission: The transmission of nerve impulses between the brain and the rest of the body is dependent on calcium. It facilitates the release of neurotransmitters, allowing nerves to communicate effectively.
Blood Clotting: Calcium is one of several chemicals necessary for the complex process of blood clotting. It acts as a co-factor for many enzymes that are involved in the coagulation cascade, helping to stop bleeding.
Hormone Release: The release of hormones and other chemicals that affect bodily functions is also regulated by calcium.

The Vicious Cycle of Calcium Deficiency

When dietary calcium is insufficient, the body maintains normal blood calcium levels by pulling the mineral from its primary storage—the bones. This preserves the critical functions of muscles, nerves, and heart, but at the expense of skeletal integrity. Over time, this consistent withdrawal weakens the bones, making them brittle and fragile. In children, this can manifest as rickets, a condition that softens and weakens bones and can lead to bowed legs and stunted growth. For adults, prolonged deficiency increases the risk of developing osteopenia and, eventually, osteoporosis.

Comparison of Calcium Sources

Obtaining calcium primarily from dietary sources is the most recommended approach. While supplements can help, they are best used to fill gaps where dietary intake is inadequate.


Food Type	Examples	Benefits	Considerations
Dairy Products	Milk, yogurt, cheese	Excellent bioavailability; most people's primary source.	Can be problematic for individuals with lactose intolerance or milk allergies.
Fortified Foods	Fortified cereals, orange juice, milk substitutes (soy, almond)	Accessible way to increase intake; useful for those avoiding dairy.	Calcium levels can vary by brand; may not be as readily absorbed as dairy.
Leafy Greens	Kale, collard greens, bok choy	Good source, especially for vegans and those with dairy intolerance.	Spinach contains calcium, but also oxalates that inhibit absorption.
Fish	Canned sardines and salmon (with bones)	Provides both calcium and vitamin D, which aids absorption.	Less common dietary source for many people.
Nuts & Seeds	Almonds, chia seeds, sesame seeds	Plant-based source; offer additional nutrients like fiber and healthy fats.	Lower calcium density per serving compared to dairy.

The Importance of Vitamin D

Calcium's effectiveness for growth is significantly boosted by vitamin D, a fat-soluble vitamin that helps the body absorb calcium from the intestines. Without sufficient vitamin D, the body cannot absorb calcium efficiently, and children and adults alike face negative health outcomes. Sunlight exposure is the primary way our bodies produce vitamin D, but it can also be obtained from oily fish, egg yolks, and fortified foods. In areas with limited sunlight, supplements may be necessary.

Conclusion: A Lifelong Commitment to Calcium

To ensure healthy growth and robust bones for life, prioritizing adequate calcium intake is crucial, particularly during childhood and adolescence. Beyond its foundational role in building and maintaining the skeleton, calcium is a workhorse mineral that supports muscle function, nerve signaling, and blood clotting. A balanced diet rich in calcium, coupled with sufficient vitamin D and regular weight-bearing physical activity, provides the best foundation for a strong skeletal system. For those with dietary restrictions or specific health concerns, consulting a healthcare provider can help determine the right approach to meeting daily calcium needs and ensuring long-term health.

Visit OrthoInfo for comprehensive information on bone health.

Frequently Asked Questions

The primary function of calcium is to build and maintain strong bones and teeth, providing them with structure and hardness. However, it is also crucial for muscle function, nerve signaling, and blood clotting.

Children and adolescents require higher amounts of calcium because this is a critical period for building peak bone mass. A large portion of a person's total skeletal mass is acquired during this time, and a high intake ensures the strongest possible bones for life.

A chronic calcium deficiency in children can lead to weak, soft bones, a condition known as rickets. This can cause stunted growth, skeletal deformities like bowed legs, and an increased risk of fractures later in life.

Excellent sources of calcium include dairy products like milk, yogurt, and cheese. For those who are lactose intolerant or vegan, good alternatives include calcium-fortified plant-based milks and juices, tofu, canned fish with bones (like sardines), and dark leafy greens such as kale and broccoli.

Vitamin D is essential because it helps the body absorb calcium from the intestines. Without sufficient vitamin D, the body cannot utilize the calcium from food effectively to build strong bones.

Yes, it is possible to get enough calcium without dairy by consuming a variety of calcium-rich and fortified foods. Good non-dairy sources include calcium-fortified soy milk, tofu, leafy green vegetables, and some types of fish.

Calcium supplements should be considered only when dietary intake is not sufficient to meet daily requirements, and only after consulting a healthcare professional. A balanced diet is always the preferred method for obtaining nutrients.