At first you must consult with your doctor whether you need calcium supplement. It is important for two groups:
1. Persons who do not get enough calcium from their food.
2. Women in menopause.
The role of calcium in bone health is indisputable. The amount of calcium absorbed is dependent on estrogen level, vitamin D level and the type of calcium supplement. The acidic condition in the intestine plays a role in calcium absorption.

The available different types of calcium supplements include:

• Calcium Citrate
• Calcium Gluconate
• Calcium Lactate
• Calcium Carbonate
• Bone meal
• Oyster Shell
• Coral Calcium

Calcium Citrate, Calcium Gluconate and Calcium Lactate are very good, but the elemental calcium is low and enough tablets must be taken. These tablets can be taken at any time of the day. Calcium Carbonate supplement must be taken after the meal. This brings a problem that excess calcium may disturb the absorption of iron which very important to form the hemoglobin.

The natural supplements like bone meal, oyster shell and coral calcium can contain poisonous heavy metals and so these must be avoided.

How to take the calcium supplement? Calcium Citrate, Calcium Gluconate and Calcium Lactate can be taken in-between two meals so that they do not disturb iron absorption. During perimenopause and post menopause it is better to take with vitamin D to support the absorption. Others must not need vitamin D with calcium. But if you live in a place where the sun is rare then it is better to take with vitamin D.

Another important point you must keep in your mind is that calcium supplement and magnesium supplement should not be taken together. Do not buy supplements where calcium and magnesium are present.