Daily How Much

A 3-ounce serving of canned sardines with bones provides about 325 mg of calcium, roughly 33% of the daily adult requirement.

A 3-ounce serving of canned salmon with bones provides about 180 mg of calcium, while the same amount of fresh, boneless salmon has only about 36 mg.

One cup of shredded romaine lettuce contains about 20 milligrams of calcium, though the amount varies by growing conditions and variety.

Rice contains very little calcium — a cup of cooked white rice has roughly 2 to 6 milligrams, and brown rice has about 19.5 milligrams.

Most prenatal vitamins contain 200 to 300 mg of calcium per serving, typically falling short of the 1,000 mg daily need during pregnancy.

A medium russet potato with skin contains roughly 22 mg of calcium, which is only about 2% of the daily recommended value.

A single tablespoon of regular peanut butter contains about 7 to 15 mg of calcium, roughly 1% of the daily recommended intake for adults.

An 8-ounce serving of unfortified orange juice has about 27 mg of calcium, while calcium-fortified varieties provide 300–350 mg per cup.

Plain oats contain roughly 54 mg of calcium per 100 grams, while a single packet of fortified instant oatmeal can deliver 100 to 150 mg.

Plain oats contain about 21 mg of calcium per half-cup dry, while fortified instant oatmeal can provide 100–215 mg per serving.