Re: Re: The low down on ferritin/Iron Sources

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Iron in the Vegan Diet

by Mangels, Ph.D., R.D.

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Topics in this article:

a.. Summary

b.. Heme vs. Non-heme Iron

c.. Iron Status in Vegans

d.. Table 1: Iron Content of Selected Vegan Foods

e.. Table 2: Comparison of Iron Sources

f.. Table 3: Sample Menus Providing More Than 15 mg of Iron

g.. References on Iron

h.. Excerpted from the book Simply Vegan: Quick Vegetarian Meals by Debra

Wasserman. Nutrition section by Mangels Ph.D., R.D. (ISBN

0-931411-20-3)

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Summary

Dried beans and dark leafy green vegetables are especially good sources of

iron, better on a per 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 do

meat eaters.

Heme vs. Non-heme Iron

Iron is an essential nutrient because it is a central part of hemoglobin

which carries oxygen in the blood. Iron deficiency anemia is a worldwide

health problem which is especially common in young women and in children.

Iron is found in food in two forms, heme and non-heme iron. Heme iron, which

makes up 40 percent of the iron in meat, poultry, and fish is well absorbed.

Non-heme iron, 60 percent of the iron in animal tissue and all the iron in

plants (fruits, vegetables, grains, nuts) is less well absorbed. Some might

expect that since the vegan diet contains a form of iron which is not that

well absorbed, vegans might be prone to developing iron deficiency anemia.

However, recent surveys of vegans and vegetarians [1, 2, 3] have shown that

iron deficiency anemia is no more common among vegetarians than among the

general population.

Iron Status in Vegans

The reason for the satisfactory iron status of many vegans may be that

commonly eaten foods are high in iron, as Table 1 shows. In fact, if the

amount of iron in these foods is expressed as 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, you would have to eat

340 calories of sirloin steak to get the same amount of iron as found in 100

calories of spinach.

Another reason for the satisfactory iron status of vegans is that vegan

diets are high in vitamin C. Vitamin C acts to markedly increase absorption

of non-heme iron. Adding a vitamin C source to a meal increases non-heme

iron absorption up to six-fold which makes the absorption of non-heme iron

as good or better than that of heme iron [4].

Fortunately, many vegetables, such as broccoli and bok choy, which are high

in iron are also high in vitamin C so that the iron in these foods is very

well absorbed. Commonly eaten combinations, such as beans and tomato sauce

or stir-fried tofu and broccoli, also result in generous levels of iron

absorption.

It is easy to obtain plenty of iron on a vegan diet. Table 3 shows several

menus which would meet the RDA [5] of 15 milligrams of iron per day for an

adult woman. Men and post-menopausal women need about one-third less iron,

10 milligrams daily.

Both calcium and tannins (found in tea and coffee) reduce iron absorption.

Tea, coffee, and calcium supplements should be used several hours before a

meal which is high in iron [6].

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References

1. 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.

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Table 1: Iron Content of Selected Vegan Foods

FOOD AMOUNT IRON (mg)

Soybeans, cooked 1 cup 8.8

Blackstrap molasses 2 Tbsp 7.0

Lentils, cooked 1 cup 6.6

Tofu 4 oz 0.7-6.6

Quinoa, cooked 1 cup 6.3

Kidney beans, cooked 1 cup 5.2

Chickpeas, cooked 1 cup 4.7

Lima beans, cooked 1 cup 4.5

Pinto beans, cooked 1 cup 4.5

Veggie burger,

commercial 1 patty 1.1-4.5

Black-eyed peas, cooked 1 cup 4.3

Swiss chard, cooked 1 cup 4.0

Tempeh 1 cup 3.8

Black beans, cooked 1 cup 3.6

Bagel, enriched 3 oz 3.2

Turnip greens, cooked 1 cup 3.2

Prune juice 8 oz 3.0

Spinach, cooked 1 cup 2.9

Beet greens, cooked 1 cup 2.7

Tahini 2 Tbsp 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 oz 1.4

Tomato juice 8 oz 1.4

Veggie hot dog 1 hot dog 1.4

Almonds 1/4 cup 1.3

Peas, cooked 1 cup 1.3

Green beans, cooked 1 cup 1.2

Kale, cooked 1 cup 1.2

Sesame seeds 2 Tbsp 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 for post-menopausal women

and 15 mg/day for pre-menopausal women.

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Table 2: Comparison of Iron Sources

FOOD IRON (mg/100 calories)

Spinach, cooked 5.4

Collard greens, cooked 3.1

Lentils, cooked 2.9

Broccoli, cooked 2.1

Chickpeas, cooked 1.7

Sirloin steak,choice,broiled 1.6

Figs, dried 0.8

Hamburger, lean, broiled 0.8

Chicken, roasted, no skin 0.6

Flounder, baked 0.3

Pork Chop, pan fried 0.2

Milk, skim 0.1

Note that the top iron sources are vegan.

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Table 3: Sample Menus Providing More Than 15 milligrams of Iron

IRON (mg)

Breakfast:

1 serving Oatmeal Plus (p. 23) 3.8

Lunch:

1 serving Tempeh/Rice Pocket

Sandwich (p. 94) 4.7

10 Dried Apricots 1.6

Dinner:

1 serving Black-Eyed Peas

and Collards (p. 76) 2.1

1 serving Corn Bread (p. 21) 2.6

1 slice Watermelon 1.0

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TOTAL 15.8

Breakfast:

Cereal with 8 ounces

of Soymilk 1.5

Lunch:

Kidney Bean Chili

(1 cup kidney beans) 5.2

1/4 cup Sunflower Seeds 1.2

1/4 cup raisins 1.1

Dinner:

4 ounces Seitan stir-fried with 4.0

1 cup Bok Choy 1.8

and sprinkled with

2 Tbsp Sesame Seeds 1.2

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TOTAL 16.0

Additional foods should be added to these menus to provide adequate calories

and to meet additional nutritional requirements.