Normal Calcium Balance

Why is calcium important?

Calcium is important for the human body as it helps in

1. Muscle contraction

2. Nerve conduction

3. Blood coagulation

4. Release of enzymes & hormones

How is the blood Calcium regulated?

A very delicate balance between the blood & the bone maintains this level. Of the total body calcium 99% is stored in the bone; the remaining 1% is in the blood. The parathyroid glands help in maintaining this level. Parathyroid glands are situated next to the Thyroid gland, that is why they are called that but they have no relation to thy Thyroid gland or Thyroid hormone.


The parathyroid glands are four small glands situated on either side of the thyroid gland. They produce a hormone called as parathyroid hormone (PTH), which helps in maintaining blood calcium levels. Vitamin D & sun expossure also play an important role in maintaining blood calcium levels.

What is the daily requirement of Calcium?

The National Osteoporosis Foundation recommends that all adults have a daily dietary intake of 1000 to 1200 mg of calcium each day.

What are the foods rich in Calcium?

The main sources of calcium in the diet are dairy products (milk, yogurt, cheese, curd) and green leafy vegetables.

Quantities of foods containing 500 mg of Elemental Calcium:

  • Milk – 14 oz.

  • Calcium fortified Milk – 8 oz.

  • Vanilla milkshake – 12 oz.

  • Yogurt, plain, low-fat – 10 oz.

  • Ice cream – 2 3/4 cups

  • Custard – 1 2/3 cups

  • Cheese – 1 1/4 cups

  • Tofu – 1 3/4 cups

  • Cheese pizza – 3 slices

Who are the people at risk for developing Calcium related problems?

Osteoporosis risk factors that cannot be changed are:

• Being female

• Postmenopausal

• Having a small skeleton

• Being Caucasian / Asian

• Family history of osteoporosis and fractures

• Advanced age

Osteoporosis risk factors that can be changed are:

• Medications with negative affects on bone

• Inadequate or excessive intake of nutrients

• Sedentary – no weight bearing activity

• Excessive exercise

• Low body weight

• Cigarette smoking

• High alcohol consumption

What can be done to lower the risk of osteoporosis?

All to lower their risk can do two very important things: be physically active and take adequate calcium. If a person picked the one thing that would have the greatest impact on his/her life and lower the risk for a number of late effects and common adult health problems, it would be to make a lifetime habit of being physically active. Regular exercise, four times a week for about thirty minutes, makes a huge difference in the strength of our bones.

Suggestions for exercise:

  • Simple walking is GREAT!

  • If you are not active, begin slowly and build up each week

  • Alternate the types of exercise to keep it fun.

  • Use other ways to increase your activity level. Use the stairs rather than the elevator. When weather permits, park a few blocks from the office and walk.

Who should take Calcium supplements?

All people with an increased risk of osteoporosis should take Calcium supplementation.

Calcium supplementation is available in various forms. The RDA for calcium intake is based on the amount of elemental calcium in the supplement taken. The most commonly available is the Calcium carbonate; 500mg of this contains only 200mg of elemental Calcium. Hence at least 1gm of this is needed to give you approximately 400mg of elemental calcium.

There are other supplements which are available which contain vit.D along with calcium. While taking these supplements, a word of caution about the blood level of Calcium, as they tend to go up and cause other problems.