Table 1.

Comparing sources for absorbable calcium

Source	Serving sizea (g)	Calcium contentb (mg/serving)	Estimated absorption efficiencyc (%)	Absorbable Ca/servingd (mg)	Servings needed to = 1 cup milk
Foods
Milk	240	290	32.1		1.0
Beans, pinto	86	44.7	26.7	11.9	8.1
Beans, red	172	40.5	24.4	9.9	9.7
Beans, white	110	113	21.8	24.7	3.9
Bok choy	85	79	53.8	42.5	2.3
Broccoli	71	35	61.3	21.5	4.5
Cheddar cheese	42	303	32.1	97.2	1.0
Cheese food	42	241	32.1	77.4	1.2
Chinese cabbage flower leaves	85	239	39.6	94.7	1.0
Chinese mustard green	85	212	40.2	85.3	1.1
Chinese spinach	85	347	8.36	29	3.3
Kale	85	61	49.3	30.1	3.2
Spinach	85	115	5.1	5.9	16.3
Sugar cookies	15	3	91.9	2.76	34.9
Sweet potatoes	164	44	22.2	9.8	9.8
Rhubarb	120	174	8.54	10.1	9.5
Whole wheat bread	28	20	82.0	16.6	5.8
Wheat bran cereal	28	20	38.0	7.54	12.8
Yogurt	240	300	32.1	96.3	1.0
Fortified foods
Tofu, calcium-set	126	258	31.0	80.0	1.2
Orange juice with Ca citrate malate	240	300	36.3	109	0.88
Soy milk with tricalcium phosphate	240	300	24	72	1.3
Bread with calcium sulfate	16.8	300	43.0	129	0.74

Reprinted with permission from Springer Publishing [33]

^aBased on a one-half cup serving size (∼85 g for green leafy vegetables) except for milk and fruit punch (1 cup or 240 mL) and cheese (1.5 oz)

^bTaken from Refs. [34] and [35] (averaged for beans and broccoli processed in different ways) except for the Chinese vegetables which were analyzed in our laboratory

^cAdjusted for load using the equation for milk (fractional absorption = 0.889–0.0964 ln load) then adjusting for the ratio of calcium absorption of the test food relative to milk tested at the same load, the absorptive index [36]

^dCalculated as calcium content × fractional absorption