Calcium carbonate is the most common form of calcium in supplements. This form should be taken with meals. Calcium citrate is more expensive, but dissolves more readily and may be appropriate for those over 50 or those who have decreased stomach acid. This form is less concentrated, so more tablets must be taken to get the same amount of calcium. Wheat bran can inhibit absorption of calcium, so avoid taking the supplement with a meal containing wheat bran.
Vitamin D is necessary for optimal calcium absorption.
Many supplements contain alpha tocopherol alone, but the antioxidant effect is best when vitamin E consists of mixed tocopherols, especially gamma tocopherol. Natural vitamin E contains mixed tocopherols. However, the natural form is more expensive, so price comparisons will need to be done to determine whether the natural form is worth buying. Vitamin C is equally absorbed in any form. The chewable form may acidify the mouth to the point of destroying tooth enamel.