Calcium supplements compared
We compare what each label says: calcium per serving, form, how big a serving is and how many you get. We have not tested any product, and we do not say how much you should take.
General information only, not medical advice. Ask a doctor or pharmacist before starting calcium, especially if you are pregnant, take medicines or have a health condition. Medical disclaimer.
Last checked November 10, 2026. How we evaluate · Corrections and updates
What the official figures say
The US Food and Drug Administration publishes one reference figure for each nutrient, the Daily Value (FDA, content current as of March 5, 2024):
- FDA Daily Value for calcium: 1300 mg a day, the figure the %DV on labels is based on.
The FDA describes Daily Values as the recommended amounts of nutrients to consume or not to exceed each day, and the %DV on a Supplement Facts label is based on them. It is one figure for the label, so it does not show differences by age, sex or pregnancy, or an upper limit. The FDA Daily Value table does not give an upper limit, and we state none. The NIH Office of Dietary Supplements publishes a fact sheet on calcium; we have not read it for this page, and we link it as a place to look for amounts by age, sex and pregnancy and for upper limits. Ask a doctor or pharmacist about medicines and about any serving above the Daily Value. Source: FDA, Daily Value on the Nutrition and Supplement Facts Labels, content current as of March 5, 2024.
How to read a calcium label
- Calcium, not the compound. In the table, the Per serving column is the calcium amount as recorded in the label record, which may differ from the weight of a compound named in the product title. Compare that column.
- Serving size. Check how many capsules or tablets make one serving, because the label's per-serving amount refers to that whole serving.
- Form. The label may name a form, such as citrate or carbonate.
- Percent Daily Value. The %DV on a label compares one serving with the Daily Value above. The records here give it for adults and children 4 or more years of age.
- Other ingredients. Read the "Other ingredients" list for allergens and added ingredients.
- Independent testing. A testing or certification mark on a label is a statement on the label record, and we have not checked any mark with the certifier. The table quotes the marks a record states (Kosher, Halal and GMP statements are not listed). Check each one on the certifier's own site.
- Your total. The amounts on different labels add up across every supplement and multivitamin.
Comparison
Only products whose label data we have read appear here: on the maker's own page, or in the National Institutes of Health's Dietary Supplement Label Database (DSLD), which records labels as submitted. A label can change after it was recorded. Selection is not a sales ranking. We will add Amazon best-seller positions only with a dated source.
| Product | Per serving | % DV on label | Servings | Form | Marks on the label | Label record |
|---|---|---|---|---|---|---|
| Thorne Calcium, 120 Capsule(s) | 250 mg per serving (1 Capsule(s)) | 19% | 120 | DimaCal (as listed in the DSLD record) | NSF Contents Certified | Source |
| NOW Calcium Hydroxyapatite Caps, 120 Capsule(s) | 500 mg per serving (2 Capsule(s)) | 38% | 60 | Calcium hydroxyapatite (product name; the DSLD record lists no ingredient form) | No testing mark stated in the record | Source |
| Garden of Life Vitamin Code Raw Calcium, 120 Vegetarian Capsule(s) | 1100 mg per serving (4 Capsule(s); the record's directions split it across two meals) | 85% | 30 | Algae (as listed in the DSLD record) | NSF Certified Gluten-Free; Non-GMO Project Verified | Source |
| Garden of Life MyKind Organics Organic Plant Calcium, 180 Vegan Tablet(s) | 800 mg per serving (3 Tablet(s)) | 62% | 60 | Organic algae (as listed in the DSLD record) | Gluten-Free Certification Organization (GFCO); Non-GMO Project Verified; Certified Vegan (Vegan.org); USDA Organic | Source |
All 4 products print a %DV, from 19% to 85% of the Daily Value. The Garden of Life Raw Calcium record lists 1,100 mg per serving of 4 capsules, split across two meals in its directions, under the ingredient name 'Calcium, Natural'. Check that figure on the maker's label. A clinician or pharmacist can answer questions about any supplement serving.
Marks are quoted from each product's label record and have not been checked with the certifier. Kosher, Halal and GMP statements are not listed.
Products are added as their labels are read. Where a maker's site blocks automated reading, we wait until the label is available on the maker's page or in the DSLD instead of copying it from a retailer.
More comparisons
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Questions
Does a higher dose mean a better product?
A higher dose is a larger number on the label, not a measure of quality. We do not rank products by dose.
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