Iron in the Vegan diet
Dried beans and dark leafy vegetables are excellent sources of iron, with less calorie basis than meat. Iron absorption is increased markedly by eating foods containing vitamin C along with foods containing iron. Vegetarians do not have a higher incidence of iron deficiency than meat eaters.
Heme iron vs. Non-heme iron
Iron is an essential nutrient because it is a central part of the hemoglobin that carries oxygen in the blood. The Iron deficiency anemia is a worldwide health problem especially common in young women and children.
The iron found in food in two forms: heme and non-heme iron. Heme iron, which makes up 40% of the iron in meat, poultry and fish is absorbed. Non-heme iron, which constitutes 60% of the iron in animal tissue and all the iron in plants (fruits, vegetables, grains, nuts), it is harder to absorb. Some think that the fact that the vegan diet doesn’t contain a form of iron that is easily absorbed, vegans might be prone to develop iron-deficiency anemia. However, recent studies of vegans and vegetarians [1, 2, 3] have shown that the incidence of anemia is common among vegetarians than among the general population.
The level of iron in vegans
The reason for the satisfactory level of iron in many vegans may lie in the fact that the foods eaten are high in iron, as shown in Table 1. In fact, if the amount of iron in these foods is expressed in milligrams of iron per 100 calories, many foods eaten by vegans are superior to animal-derived foods. This concept is illustrated in Table 2. For example, to get the same amount of iron in 100 calories of spinach would have to eat 340 grams of sirloin.
Another reason for the satisfactory iron status of vegans is that vegan diets are high in vitamin C. Vitamin C acts to non-heme iron absorption. Add vitamin C to a meal increases the absorption of non-heme iron up to six times, which makes the absorption of non-heme iron as good or better than the heme iron [4]. Fortunately, many vegetables such as broccoli and Chinese cabbage (bok choy), rich in iron, are also rich in vitamin C, so that the iron in these foods is very well absorbed. Commonly eaten combinations, such as beans in tomato sauce or stir-fried tofu and broccoli, also result in generous levels of iron absorption.
It's easy to get plenty of iron on a vegan diet. Table 3 shows several menus that you can get the RDA or recommended daily allowance [5] of 15 milligrams per day for an adult woman. Men and postmenopausal women need about one third less iron is 10 milligrams daily.
Both calcium and tannins (containing the tea and coffee) reduce iron absorption. Tea, coffee and calcium supplements should be taken several hours before a meal rich in iron [6].
References
1. Anderson BM, Gibson RS, Sabry JH: The iron and zinc status of long-term vegetarian women. Am J Clin Nutr 1981; 34: 1042-1048.
2. Latta D and Liebman M: Iron and zinc status of vegetarian and non-vegetarian males. Nutr Rep Int 1984; 30: 141-149.
3. Helman AD and Darnton-Hill I: Vitamin and iron status in new vegetarians. Am J Clin Nutr 1987; 45: 785-789.
4. Hallberg L: Bioavailability of dietary iron in man. Ann Rev Nutr 1981; 1: 123-147.
5. Food and Nutrition Board, National Research Council: Recommended Dietary Allowances, 10th ed. Washington, DC: National Academy Press, 1989.
6. Gleerup A, Rossander Hulthen L, Gramatkovski E, et al. Iron absorption from the whole diet: comparison of the effect of two different distributions of daily calcium intake. Am J Clin Nutr 1995; 61: 97-104.
Table 1: Contents of iron in vegan food choices
FOOD, AMOUNT, IRON (mg):
- Soybeans, cooked, 1 cup, 8.8
- Blackstrap molasses, 2 tablespoons, 7.0
- Lentils, cooked, 1 cup, 6.6
- Tofu, 4 oz ,0.7-6 .6
- Quinoa, cooked, 1 cup, 6.3
- Beans, cooked, 1 cup, 5.2
- Chickpeas, cooked, 1 cup, 4.7
- Green Beans, cooked, 1 cup, 4.5
- Pinto beans, cooked, 1 cup, 4.5
- Veggie burger, commercial 1 unit, 1.1-4.5
- Cowpeas, cooked, 1 cup, 4.3
- Swiss chard, cooked, 1 cup, 4.0
- Tempeh, 1 cup, 3.8
- Black beans, cooked, 1 cup, 3.6
- Breadsticks, enriched, 3 ounces, 3.2
- Turnip greens, cooked, 1 cup, 3.2
- Prune juice, 8 ounces, 3.0
- Spinach, cooked, 1 cup, 2.9
- Chard, cooked, 1 cup, 2.7
- Tahini, 2 tablespoons, 2.6
- Raisins, 1 / 2 cup, 2.2
- Cashews, 1 / 4 cup, 2.0
- Figs, dried 5 medium 2.0
- Seitan 4 oz 2.0
- Bok choy, cooked 1 cup 1.8
- Bulgur, cooked 1 cup 1.7
- Apricots, dried 10 halves 1.6
- Potato 1 large 1.4
- Soy yogurt 6 ounces 1.4
- Tomato juice 8 ounces 1.4
- Vegetarian Hot Dog 1 Unit 1.4
- Almonds 1 / 4 cup 1.3
- Peas, cooked 1 cup 1.3
- Green beans, cooked 1 cup 1.2
- Collards, cooked 1 cup 1.2
- 2 tablespoons sesame seeds 1.2
- Sunflower seeds 1 / 4 cup 1.2
- Broccoli, cooked 1 cup 1.1
- Brussels sprouts, cooked 1 cup 1.1
- Millet, cooked 1 cup 1.0
- Prunes 5 medium 1.0
- Watermelon, 1 / 8 Medium 1.0
Sources: USDA Nutrient Data Base for Standard Reference, Release 12, 1998. Manufacturer 's information.
The RDA for iron is 10 mg / day for adult men and postmenopausal women and 15 mg / day for premenopausal women.
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Table 2: Comparison of Iron Sources
FOOD IRON (mg/100 calories):
- Spinach, cooked 5.4
- Cabbage, cooked 3.1
- Lentils, cooked 2.9
- Broccoli, cooked 2.1
- Garbanzo beans, cooked 1.7
- Sirloin premium
- Grilled 1.6
- Figs, dried 0.8
- Hamburger, fat, fried 0.8
- Chicken, roasted, peeled 0.6
- Flounder, baked 0.3
- Pork chop, fried 0.2
- Milk, skim 0.1
Notice that the major iron sources are vegan.
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Table 3: Examples of menus that provide more than 15 milligrams of iron
IRON (mg)
Breakfast:
1 serving of porridge
Oatmeal Plus (p. 23) 3.8
Food:
Tempeh 1 sandwich or rice (p. 94) 4.7
10 Dried Apricots 1.6
Dinner:
1 serving of beans, cowpeas
with cabbage (p. 76) 2.1
1 serving of cornbread (p. 21) 2.6
1 slice of watermelon 1.0
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TOTAL 15.8
Breakfast:
Cereal with 8 ounces of milk
Soy 1.5
Food:
Chili Beans
(1 cup cooked) 5.2
1 / 4 cup sunflower seeds 1.2
1 / 4 cup raisins 1.1
Dinner:
4 ounces Seitan stir-fry with 4.0
1 cup Chinese cabbage 1.8
sprinkled with
2 tablespoons sesame seeds 1.2
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TOTAL 16.0
These menus have to add other foods to provide the necessary calories and meet additional nutritional requirements
By Reed Mangels, PhD, RD
The Vegetarian Resource Group
(Published in the book "Simply Vegan: Quick Vegetarian Meals " by Debra Wasserman, nutrition section by Reed Mangels)