Comparison

Calcium Citrate plus Vitamin D and Oyster Shell Calcium 500 +D

Calcium Citrate plus Vitamin D (The Vitamin Shoppe) lists 2 distinct ingredients and Oyster Shell Calcium 500 +D (21st Century) 2 (rows of one ingredient counted once); 2 are on both labels. On the site's similarity measure, which compares ingredient lists (1 for the same list, rarer ingredients counting for more; amounts are not part of it), the two formulas score 1.00: the same ingredients, at the amounts in the table below.

Amount per serving (and % of the Daily Value)
IngredientCalcium Citrate plus Vitamin DOyster Shell Calcium 500 +D
Calcium1,000 mg (77%)1,000 mg (77%)
Vitamin D10 mcg (50%)10 mcg (50%)

Amounts are per serving as DSLD gives them: Calcium Citrate plus Vitamin D, 4 tablets; Oyster Shell Calcium 500 +D, 2 tablets. Current labels entered December 2019 and July 2012. Percentages of the Daily Value from 21 CFR 101.9. Source: NIH ODS Dietary Supplement Label Database.

Each product on its own