Calcium Group
Understanding Dietary Presence and Physiological Roles
Overview
Calcium is the most abundant mineral in the human body, with 99% residing in bones and teeth. As a macronutrient, it appears widely in diverse food sources and plays central roles in skeletal structure, muscle function, and various cellular processes. Understanding calcium's dietary presence supports appreciation of diverse nutritional patterns across cultures.
Dietary Calcium Sources
Calcium appears naturally in numerous foods, making diverse dietary patterns naturally calcium-rich:
Leafy Greens
- Collard greens
- Kale
- Water spinach
- Bok choy
- Dandelion greens
Seeds & Legumes
- Sesame seeds
- Tahini
- Beans
- Lentils
- Chickpeas
Fish & Soy
- Tofu (calcium-set)
- Tempeh
- Canned fish with bones
- Fish paste
Other Sources
- Almonds
- Blackstrap molasses
- Dried figs
- Fortified plant beverages
Absorption Factors
Calcium absorption varies with multiple factors:
| Factor | Impact on Absorption |
|---|---|
| Vitamin D Status | Enhances calcium absorption in the intestine |
| Food Source | Plant sources vary; some contain compounds that reduce absorption |
| Stomach Acid | Necessary for calcium ionization and absorption |
| Age | Absorption efficiency decreases with age |
| Individual Physiology | Genetic and health factors influence absorption rates |
| Portion Size | Smaller, frequent doses promote better absorption than large single doses |
Physiological Roles
Calcium functions throughout the body in:
- Bone Structure: Forms the mineral matrix providing skeletal rigidity and support
- Muscle Contraction: Enables the sliding filament mechanism during muscle fiber contraction
- Nerve Transmission: Facilitates synaptic transmission and neuronal signaling
- Blood Coagulation: Acts as a cofactor in the coagulation cascade
- Enzyme Function: Serves as a cofactor for numerous enzymes
- Hormone Secretion: Regulates secretion of various hormones
- Blood Pressure Regulation: Participates in vascular tone and blood pressure control
Reference Values
International reference intakes for calcium vary by age and life stage. Most guidelines recommend 1000-1200 mg daily for adults, with adjustments for children, adolescents, and older adults. Meeting calcium needs through diverse food sources remains the foundational approach in nutritional practice.
Continue Exploring
Discover complementary minerals and nutrients.