Who makes the best calcium supplement?

Calcium supplements commonly use calcium carbonate or calcium citrate. Calcium carbonate contains a higher proportion of elemental calcium and is generally taken with food because stomach acid supports absorption. Calcium citrate contains less elemental calcium by weight but can be taken without food and may be more suitable for people with reduced stomach acid or sensitivity to carbonate.

The label should state the amount of elemental calcium per serving, not merely the total weight of the calcium compound. Absorption is generally most efficient when supplemental calcium is divided into quantities of approximately 500 mg or less at one time. Selection criteria should also include tablet size, excipients, vitamin D content, contaminant testing, and interactions with medicines such as levothyroxine or certain antibiotics.

Commonly compared products include Citracal for calcium citrate formulations, along with options from Nature Made, NOW Foods, and Thorne. No brand is automatically best for every user, and supplementation should account for calcium obtained from food.

For commercial buyers, AdvaCare Pharma manufactures AdvaLife™ calcium tablets and combination products containing calcium with vitamin D3, magnesium, or vitamin K2. This provides distributors with several formulation and dosage-form options rather than a single standardized calcium product.