Calcium is the most abundant mineral in the human body, with 99% of it stored in our bones and teeth. The remaining 1% plays a crucial role in various cellular functions. Calcium is a critical component of a healthy diet, and our body tightly regulates calcium levels in the blood through hormonal pathways.
Functions of Calcium
- Bone health: Calcium is a primary component of bones and teeth, providing strength and structural support.
- Muscle function: Calcium plays a critical role in muscle contraction, including skeletal, smooth, and cardiac muscles.
- Nerve function: Calcium is essential for nerve impulse transmission, allowing cells to communicate effectively.
- Blood clotting: Calcium is involved in blood coagulation, helping to prevent excessive bleeding in case of injury.
- Enzyme activation: Calcium is a cofactor for various enzymes, participating in numerous biochemical reactions.
Good Sources of Calcium
- Dairy products: Milk, yogurt, and cheese are rich sources of calcium.
- Leafy green vegetables: Kale, spinach, collard greens, and pak choi (Chinese cabbage) contain substantial amounts of calcium.
- Fish: Sardines and salmon, especially when eaten with bones, are good sources of calcium.
- Nuts and seeds: Almonds, sesame seeds, and chia seeds are calcium-rich options.
- Fortified foods: Calcium-fortified foods such as orange juice, cereals, and plant-based milk are widely available.
How Much Calcium Do We Need?
(Based on NIH recommendations): The recommended daily allowance (RDA) for calcium varies depending on age, sex, and life stage. Some general guidelines are:
- Infants 0-6 months*: 200 mg/day (Milligram)
- Infants 7-12 months*: 260 mg/day
- Children 1-3 years: 700 mg/day
- Children 4-8 years: 1,000 mg/day
- Children 9-13 years: 1,300 mg/day
- Adolescents 14-18 years: 1,300 mg/day
- Adults 19-50 years: 1,000 mg/day
- Adults 51-70 years (males): 1,000 mg/day
- Adults 51-70 years (females): 1,200 mg/day
- Pregnant and breastfeeding women: 1000 mg/day
- Adults 71 years and older: 1,200 mg/day
(*) Adequate intake (AI)
What Are The Signs of Calcium Deficiency?
Calcium deficiency, or hypocalcaemia, can manifest in various ways. Some common signs and symptoms include:
- Muscle cramps and spasms
- Numbness or tingling in extremities
- Weak or brittle nails
- Dental problems, such as tooth decay and gum disease
- Osteoporosis or osteopenia, characterised by low bone density
What Happens If I Take Too Much Calcium?
Excessive calcium intake, or hypercalcemia, can lead to several health issues, such as:
- Kidney stones: High calcium levels can lead to the formation of calcium-based kidney stones.
- Impaired kidney function: Excess calcium can cause calcification in the kidneys, affecting their ability to filter waste.
- Heart problems: Elevated calcium levels can lead to calcification in blood vessels and heart valves, increasing the risk of cardiovascular diseases.
- Constipation and gastrointestinal issues: Excess calcium can cause digestive problems such as constipation, bloating, and gas.
- Interference with nutrient absorption: High calcium levels can interfere with the absorption of other minerals, such as iron, zinc, and magnesium.