ABCDEFGHIJKLMNOPQRSTUVWXYZAAAB
1
ServingGramsKCALCalcium
(mg)
Calcium
absorption
(%)
Calcium
absorbed
(mg)
Oxalate
(mg)
References / NotesAmount for 1 servingCalcium absorbed / 33Soluble
oxalate
(mg)
Phytate
(mg)
2
3
Good Plant Food Sources of Calcium
4
Apple juice, calcium fortified2500.42105Calcium absoprtions measured by Andon, 1996.
5
Bok choy, shredded, boiled1 cup170201580.406334Calcium absorption and oxalate measured by Weaver, 1997.2/3 cup1.9
6
Broccoli, chopped, boiled1 cup15655620.53337Calcium absorption measured by Heaney, 1993. Phytates provided by Weaver, 2023. Oxalate measured by Chai, 2005.1 cup1.04
7
Brussels sprouts, boiled1 cup15656560.643610Calcium absorption estimated by Weaver, 1994. Oxalate measured by Chai, 2005.1 cup1.14
8
Collard greens, chopped, boiled1 cup190632680.349110Calcium absorption estimated using algorithm from Weaver, 2023. Oxalate provided by Harvard, 2007.1/2 cup2.8
9
Fenugreek leaves (Methii), cooked1 cup140483840.218248Indian Food Composition Tables (2017) Calcium absorption estimated by Amalraj, 2014. 140 g estimated to be about 1 cup based on similar cooked greens.1/2 cup2.513
10
Figs, dried1/2 cup74.51861210.384644Calcium absorption estimated using algorithm from Weaver, 2023. Oxalate provided by Harvard, 2007. 1 fig = 8.4 g.1/2 cup1.4
11
Jute, boiled1 cup87321840.40741Calcium absorption based on kale. Oxalate measured by Agbo, 2009.1/2 cup
12
Kale, chopped, boiled1 cup118431770.40711Calcium absorption measured by Heaney, 1990. Oxalate provided by Harvard, 2007.1/2 cup2.1
13
Molasses, blackstrap1 tbsp2160191Very little oxalate per Harvard, 2007.1 tbsp0.9
14
Moringa powder≥ 970.34≥ 33Moringa powder with at least 97 mg of calcium should result in at least 33 mg of caclium absorbed. Calcium absorption estimated by Allen, 2014 via in vitro modeling (similar to Yunn, 2020).
15
Mustard greens, chopped, boiled1 cup140361650.40664Calcium absorption measured by Weaver, 1997. Oxalate provided by Harvard, 2007.1/2 cup2.0
16
Natto1/3 cup581231270.3139Calcium absorption based on minimum for tofu.1/3 cup1.2
17
Orange juice, calcium fortified2500.3690Calcium absoprtions measured by Andon, 1996.1/2 cup2.7
18
Soymilk, calcium fortified1 cup703000.2471Nutrition label from Wildwood Organic Soymilk Unsweetened, 2013. Calcium absorption measured by Heaney, 2000.1/2 cup2.2
19
Soymilk, calcium fortified582500.2153Calcium absorption measured by Zhao, 2005.2/3 cup1.6
20
Soymilk, calcium fortified20050Calcium absorption estimation provided on the Soymilk tab of this spreadsheet.1.5
21
Soymilk, calcium fortified9400.6526Calcium absorption measured by Tang, 2010.0.8
22
Tofu, firm, with calcium salts1/2 cup126982530.3178Calcium absorption estimated by Weaver, 1994.2.4
23
Tofu, set with calcium chloride1002500.49123Calcium measured by Weaver, 2002.2,470
24
Tofu set with calcium sulfate1002000.3876Calcium measured by Weaver, 2002.2,470
25
Tofu, dried, calcium-set17803620.3813825 g
26
Tofu, firm, Trader Joe's Organic with calcium sulfate1/2 cup109861590.3860Package label and adjustments. Calcium absorption taken from Weaver, 2002.1/2 cup1.8
27
Turnip greens, chopped, boiled1 cup144291970.407928Calcium absorption estimated based on other low-oxalate greens at similar serving sizes. Oxalate based on 15 mg per 104 mg of calcium in 1 cup of chopped, raw turnip greens as provided by USDA, 2013.1/2 cup2.4
28
Water spinach (Ipomoea aquatica), chopped, raw1/2 cup5652370.409525USDA entry shows very little calcium: 45 mg Ca per 1/2 cup (56 g) but the method derived isn't clear. Himabindhu (2021) found 237 mg Ca and 25 mg of oxalate per 56 g. We estimate 0.40 calcium absorption based on bok choy with similar calcium and oxalate content.1/3 cup2.9
29
30
Other Plant Foods for Comparison
31
Almonds, dry roasted1/4 cup34210920.2119151Calcium absorption estimated by Weaver, 1994. Oxalate provided by Massey 2007.
32
Beet greens, raw1 cup38845231Oxalate provided by USDA, 2013.
33
Beets, boiled1/2 cup85371441Oxalate measured by Chai, 2005.29
34
Broccoli, chopped, raw1 cup91314312Oxalate measured by Chai, 2005.5
35
Carrots, rawmedium61252027Oxalate measured by Chai, 2005.19
36
Carrots, slices, boiled1/2 cup78272314Oxalate measured by Chai, 2005.166.66666678
37
Cashews, roasted1/4 cup341971577Oxalate provided by Harvard, 2007.50
38
Chia seeds, dry1/4 oz7354569Oxalate provided by Garland, 2020; Garland provides no source. Kidney.org lists chia seeds as "high" in oxalate.
39
Figs, raw2 pc100743519Oxalate provided by Harvard, 2007.
40
Hazelnuts, chopped, raw1/4 cup291813348-64Oxalate provided by Massey 2007.
41
Kale, raw1 cup217532Oxalate provided by Harvard, 2007.
42
Macadamia nuts, whole or halves, raw1/4 cup342412914Oxalate provided by Massey 2007.
43
Molasses, regular (not blackstrap)1 tbsp2058410Oxalate provided by Harvard, 2007.
44
Moringa (aka Drumstick) leaves, chopped, boiled1 cup4225630.3421Calcium absorption estimated by Allen, 2014 via in vitro modeling (similar to Yunn, 2020).
45
Navy beans, boiled1/2 cup911286376Oxalate provided by Harvard, 2007.
46
Okra, raw1 cup100338250Oxalate provided by USDA, 2013.
47
Orange, navel, raw1 pc140736029Oxalate provided by Harvard, 2007.
48
Pinto beans, refried, vegetarian1/2 cup130140570.171060Calcium absorption estimated by Weaver, 1994. Oxalate provided by Harvard, 2007.
49
Radish leaves1 cup1403632876Indian Food Composition Tables (2017) 140 g estimated to be about 1 cup based on similar cooked greens.32
50
Rhubarb, diced, raw1 cup1221071050.099371Calcium absorption measured by Weaver, 1997. Oxalate provided by Chai, 2005.106
51
Spinach (Spinacia oleracea), boiled1 cup180412450.0512828Calcium absorption measured by Heaney, 1988. Oxalate measured by Chai, 2005.193
52
Spinach (Spinacia oleracea), raw1 cup30730344Oxalate measured by Chai, 2005.241
53
Sweet potato, cubed, raw1 cup1331144028Oxalate provided by Harvard, 2007.
54
Swiss chard, boiled1 cup17535102749
586
Oxalate for red (provided by Chai, 2005).
Oxalate for green (provided by Chai, 2005)
212
172
55
Tahini2 tbsp301781280.212732Calcium absorption estimated by Weaver, 1994. Oxalate provided by Harvard, 2007.
56
Walnuts—chopped1/4 cup291912912Oxalate provided by Harvard, 2007.
57
Watercress, chopped, raw1 cup344410.672736Calcium absorption estimated by Weaver, 1994. Oxalate provided by USDA, 2013.
58
59
Calcium supplements
60
Calcium carbonate3000.34103Calcium absorption measured by Heaney, 1999.
61
Calcium carbonate1,0000.30301Calcium absorption measured by Heaney, 1999.
62
Calcium citrate3000.38114Calcium absorption measured by Heaney, 1999.
63
Calcium citrate1,0000.27268Calcium absorption measured by Heaney, 1999.
64
65
Cow's milk (for comparison)
66
Milk, 2% fat1 cup246123295
67
Milk2001002400.2253Calcium absorption measured by Zhao, 2005.
68
Milk160801920.2854Calcium absorption measured by Heaney, 1988.
69
Milk3216380.6525Calcium absorption measured by Tang, 2010.
70
71
Notes
72
Rationale for Determing a "Good" Source of Calcium
73
Rationale for the Serving Sizes of Leafy Greens
74
75
References
76
Agbo, Adouko & Kouame, Christophe & Mahyao, Adolphe & N'zi, Jean-Claude & Fondio, Lassina. (2009). Nutritional importance of indigenous leafy vegetables in Côte d'Ivoire. Acta Horticulturae. 361-366. 10.17660/ActaHortic.2009.806.45.
77
Andon MB, Peacock M, Kanerva RL, De Castro JA. Calcium absorption from apple and orange juice fortified with calcium citrate malate (CCM). J Am Coll Nutr. 1996 Jun;15(3):313-6.
78
Allen JC, Issa JY and Cai W. Calcium content, in vitro digestibility, and bioaccessibility in leaves of spinach (Spinacia oleracea), sweet potato (Ipomea batatas), and drumstick tree (Moringa oleifera) [version 1; peer review: 3 approved with reservations]. F1000Research 2014, 3:65.
79
Amalraj A, Pius A. Bioavailability of calcium and its absorption inhibitors in raw and cooked green leafy vegetables commonly consumed in India--an in vitro study. Food Chem. 2015 Mar 1;170:430-6. doi: 10.1016/j.foodchem.2014.08.031.
80
Chai W, Liebman M. Effect of different cooking methods on vegetable oxalate content. J Agric Food Chem. 2005 Apr 20;53(8):3027-30.
81
Garland V, Herlitz L, Regunathan-Shenk R. Diet-induced oxalate nephropathy from excessive nut and seed consumption. BMJ Case Rep. 2020 Nov 30;13(11):e237212.
82
Heaney RP, Dowell MS, Barger-Lux MJ. Absorption of calcium as the carbonate and citrate salts, with some observations on method. Osteoporos Int. 1999;9(1):19-23.
83
Heaney RP, Dowell MS, Rafferty K, Bierman J. Bioavailability of the calcium in fortified soy imitation milk, with some observations on method. The American journal of clinical nutrition. 2000 May 1;71(5):1166-9.
84
Heaney RP, Weaver CM, Recker RR. Calcium absorbability from spinach. Am J Clin Nutr. 1988 Apr;47(4):707-9.
85
Heaney RP, Weaver CM. Calcium absorption from kale. Am J Clin Nutr. 1990 Apr;51(4):656-7.
86
Himabindhu B, Divakar S, Pillali S, Joseph B, Krishnaja U. Quality evaluation of water spinach (Ipomea aquatica) leaves cultivated through Aquaponics. Int J Chem Stud 2021;9(1):1245-1252. DOI: 10.22271/chemi.2021.v9.i1r.11393
87
Massey LK. Food oxalate: factors affecting measurement, biological variation, and bioavailability. J Am Diet Assoc. 2007 Jul;107(7):1191-4; quiz 1195-6.
88
Oxalate Content of Foods.xls Excel sheet from Harvard University published in 2007. Reproduced in the Harvard Oxalate tab of this spreadsheet.
89
Oxalic Acid Content of Selected Vegetables. Gives amounts of oxalate in 100 g of the raw, unprepared food (according to correspondence with the USDA Nutrient Data Library 05/13/2013).
90
Tang AL, Walker KZ, Wilcox G, Strauss BJ, Ashton JF, Stojanovska L. Calcium absorption in Australian osteopenic post-menopausal women: an acute comparative study of fortified soymilk to cows’ milk. Asia Pac J Clin Nutr. 2010;19(2):243-9.
91
Weaver CM, Heaney RP, Connor L, Martin BR, Smith DL, Nielsen S. Bioavailability of calcium from tofu as compared with milk in premenopausal women. Journal of food science. 2002 Oct;67(8):3144-7.
92
Weaver CM, Heaney RP, Nickel KP, Packard PI. Calcium Bioavailability from High Oxalate Vegetables: Chinese Vegetables, Sweet Potatoes and Rhubarb. Journal of Food Science. 1997 May;62(3):524-5.
93
Weaver CM, Plawecki KL. Dietary calcium: adequacy of a vegetarian diet. Am J Clin Nutr. 1994 May;59(5 Suppl):1238S-1241S.
94
Weaver CM, Wastney M, Fletcher A, Lividini K. An Algorithm to Assess Calcium Bioavailability from Foods. J Nutr. 2023 Dec 9:S0022-3166(23)72792-2.
95
Yun YR, Oh SJ, Lee MJ, Choi YJ, Park SJ, Lee MA, Min SG, Seo HY, Park SH. Antioxidant activity and calcium bioaccessibility of Moringa oleifera leaf hydrolysate, as a potential calcium supplement in food. Food Sci Biotechnol. 2020 Sep 5;29(11):1563-1571.
96
Zhao Y, Martin BR, Weaver CM. Calcium bioavailability of calcium carbonate fortified soymilk is equivalent to cow’s milk in young women. J Nutr. 2005 Oct;135(10):2379-82.
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