Calcium

Calcium is a mineral you need to build and maintain bones and teeth. It helps against osteoporosis later in life and is also needed for proper nerve and muscle function, blood clotting and transport of other minerals in the body.

When you don't get enough calcium for a long period of time, your body can withdraw calcium from the bones. This leads to osteoporosis (osteoporosis of the bones) and increases the risk of bone fractures.

What does calcium contain?

- Milk and milk products
- Cheese
- Whole grain cereal products (such as bread)
- Green vegetables, including kale and spinach
- Drinking water (about 60 mg of calcium at 2 liters of water)

👉 Note: Calcium from dairy products is well absorbed, especially in the form of calcium phosphate. Other forms such as calcium citrate, which are slightly more absorbable, are also used in supplements.

How much calcium do you need?

The recommended daily allowance (RDA) of calcium for adults is about 1,000 mg per day.

Vitamin D is essential for proper calcium absorption.

Factors affecting uptake

- Vitamin D → stimulates absorption
- Oxalic acid (e.g. in spinach, rhubarb) → reduces absorption
- Phytic acid (in grains) → reduces absorption
- Salt, alcohol, caffeine → cause additional calcium loss through urine

What is calcium good for?

- Keeping bones and teeth strong
- Good nerve and muscle function
- Support blood clotting
- Transport of minerals in body cells

Deficiency of calcium

Risk groups:
- Women over 50 and men over 70 → lower intake, faster osteoporosis
- Children → risk of rickets (English disease) with severe deficiency and too little vitamin D

Shortage complaints:
- Muscle cramps and tingling around mouth, fingers or toes
- Increased risk of bone fractures
- In severe deficiency: tetany, laryngeal spasm, cardiac arrhythmias

Too much calcium

An intake of more than 2,500 mg per day can lead to:
- Urinary tract stones
- Calcification of kidneys or blood vessels (especially when taking antacids with calcium bicarbonate)

Calcium and the parathyroid glands

The parathyroid glands (parathyroid) make parathyroid hormone (PTH). This hormone, along with vitamin D and phosphate, regulates calcium levels in your blood. This keeps your calcium balance.

Malfunction of these glands can lead to hypoparathyroidism, with risk of severe calcium deficiency.

What can you do yourself?

- Ensure adequate sunlight → stimulates vitamin D and thus calcium absorption
- Eat plenty of green vegetables, whole grain cereals and dairy or alternatives such as A2 milk, goat or sheep milk products
- Exercise regularly → helps keep bones strong
- Avoid excessive salt, alcohol and caffeine