iron for vegans

7/28/2019 Iron for Vegans

1/6

4 Tweet 10 Vegan For Li fe

by Jack Norris, RD &Ginny Messina,

MPH, RDFor Updates: Follow @JackNorrisRD or subscribe to JackNorrisRD.com

Iron

by J ack Norris, RD | Last updated: May 2013

Contents

Summary Iron Deficiency and Anemia Meat Iron vs. Plant IronTable 1: Iron Amounts in Plant Foods Iron Deficiency in Vegetarians Low Iron Stores: Not Necessarily Unhealthy Hemochromatosis Celiac Disease Proton Pump Inhibitors Recommendations References

Summary

If you think your iron stores might be low, you can increase iron absorption by:

Adding a source of vitamin C at meals. Avoiding tea and coffee at meals.

Increasing legume (peanuts, beans, lentils, peas) intake.

Cooking foods (especially water based acidic foods like tomato sauce) in cast iron skillets.

If you think you might have iron deficiency anemia, see a doctor to find out. Supplements are available for peoplediagnosed with deficiency.

Functions of Iron

The major functions of iron are:

Energy Production

The majority of iron in the body is involved in energy production. The largest fraction is found in thehemoglobin of red blood cells and is necessary for oxygen transport throughout the body. Iron also servesas part of myoglobin for oxygen supply to muscle. Iron is involved in the electron transport system, is partof an important energy-producing enzyme, NADH dehydrogenase.

Immunity

Iron has pro-oxidation properties used by the immune system to destroy bacteria.

Required for DNA synthesis

Iron Deficiency

Iron deficiency is the most common nutrient deficiency in the U.S. There are two stages:

Home | Sit e Map

Quick Links

Recommendations

Vitamin B12

Calcium & Vitamin D

Protein

Sports Nutrition

Meal Plans

Vegan Kids

Research on Vegans

Disease Treatment

Soy & Food Allergies

Raw Foodism

Dietetics

Companion Animals

Translations

Like 89 Send

Page 1 of 6Iron

13-Jun-13http://www.veganhealth.org/articles/iron


2/6

Table 1. Iron in Plant Foods

Food Preparation Serving mg

Broccoli 1/2 C chopped boiled 0.52

Spinach 1/2 C chopped boiled 3.2

Kale 1/2 C chopped boiled 0.59

Collard greens 1/2 C chopped boiled 1.1

Swiss chard 1/2 C chopped boiled 2

Sweet potato 1/2 C baked, w/skin 0.7

Tomatoes 1/2 C cooked 0.82

Oatmeal 1/2 C cooked 1

Rice (white, long-grain, unenriched) 1/2 C cooked 0.7

Rice (white, long-grain, enriched) 1/2 C cooked 1.4

Bread whole wheat 1 slice 0.68

Tempeh 3 oz cooked 1.5

Tofu 3 oz 0.8

Soymilk 1 C 1.0 - 1.5

Edamame 1/2 C 1.8

Kidney beans 1/2 C boiled 2.6

Iron deficiency anemia (IDA) - typically measured by a hemoglobin of less than 120 g/l

Many iron deficiency symptoms are related to tissue oxygen deprivation: fatigue, rapid heart rate, palpitations,rapid breathing on exertion, and increased lactic acid production. IDA symptoms include pale skin, brittlefingernails, (koilonychia (spoon-shaped fingernails where the outer edges are raised), weakness, loss ofappetite, apathy, hair loss. impaired immunity, angular stomatitis (irritation and fissuring in the corners of thelips), glossitis (inflammation of the tongue), chronic gastritis, pica, and abnormal temperature regulation.

Many of these are symptoms of other nutritional deficiencies and diseases and therefore only a medical doctor

can properly diagnose IDA. It is relatively inexpensive to have your iron levels tested by a doctor.Iron is transported throughout the body as part of the transferrin protein and is stored as ferritin. The earlieststage of iron deficiency occurs when stores are depleted, characterized by a drop in serum ferritin levels and anincrease in total iron binding capacity (incomplete saturation of transferrin). Serum ferritin levels below 12 g/lare associated with complete depletion of storage iron. At this stage, normal red blood cell formation is impaired,but not enough to cause a measurable anemia.

IDA is characterized by small red blood cells due to a lack of hemoglobin. Low values for hemoglobinconcentration in blood, red blood cell count, hematocrit (the percentage, by volume, of red blood cells in wholeblood), mean corpuscular volume (the size of the average red blood cell), and erythrocyte hemoglobinconcentration are all potentially indicative of IDA.

Because iron deficiency is not the only cause of anemia, multiple measures of iron status should be taken todetermine if an anemia is truly from iron deficiency. The Centers for Disease Control (CDC) defines irondeficiency as abnormal values for any two of these parameters: serum ferritin, transferrin saturation, and freeerythrocyte protoporphyrin. The CDC defines iron deficiency anemia as iron deficiency with a low hemoglobinvalue.

Some health professionals believe in "sub-clinical iron deficiency" in which someone has blood measurements inthe normal range but is still having symptoms of ID or IDA. According to the National Academy of Sciences, "Thebulk of experimental and epidemiological evidence in humans suggests that functional consequences of irondeficiency (related both to anemia and tissue concentration) occur only when iron deficiency is of a severitysufficient to cause a measurable decrease in hemoglobin concentration (1)." However, other iron experts suggestthat some people have a higher-than-average normal hemoglobin level and can suffer from IDA even thoughtheir hemoglobin is in the (presumably lower end of the) normal range.

Iron is prevalent in a widevariety of plant foods,especially beans and grains.In fact, vegans' iron intakesare as high or higher thannon-vegetarians. Table 1shows the iron content ofsome plant foods as well as

the Dietary ReferenceIntakes for iron.

In meat, 65% of iron isbound to the heme molecule(from hemoglobin andmyoglobin), which isrelatively easily absorbed.The rest of the iron in meatand all iron in plants is non-heme iron (3). Non-hemeiron requires being releasedfrom food components byhydrochloric acid and thedigestive enzyme pepsin inthe stomach (3). Non-hemeiron also needs to be

shuttled from the digestivetract into the bloodstream bya protein called transferrin.

The phytates, found inlegumes and grains, andpolyphenols (includingtannins found in coffee andgreen tea, black tea, andsome herbal teas), caninhibit the absorption ofplant iron. On the otherhand, vitamin C is a strongenough enhancer of plant

Contact | Copyright 2003-2013

VeganHealth.org

Page 2 of 6Iron



3/6

Pinto beans 1/2 C boiled 1.8

Garbanzo beans 1/2 C boiled 2.4

Peas green 1/2 C boiled 1.2

Lentils 1/2 C boiled 3.3

Hummus 2 T 0.7

Peanut butter 2 T 0.6

Tahini 2 T .7 - 2.6

Walnuts 1/4 Cchopped

0.85

Almonds 1/4 C roasted 1.3

Pistachios 1/4 C dry roasted 1.2

Sunflower seeds 1/4 C dry roasted 1.2

Dried figs 1/2 C dried, raw 1.5

Raisins 1/2 C 1.4

Grape Nuts 1/2 C 16

Total, whole grain 1/2 C 8

Molasses 2 T 3.8

Taken from theUSDA National Nutrient Database or food labels.

iron and can overcome theinhibitors in plant foods.

One study found thatvarious doses of phytatereduced iron absorption by10 to 50%. But adding 50mg of vitamin Ccounteracted the phytate,and adding 150 mg ofvitamin C increased ironabsorption to almost 30%.Similarly, in the presence ofa large dose of tannic acid,100 mg of vitamin Cincreased iron absorptionfrom 2 to 8% (13).

In another study, vegetarianchildren with IDA and lowvitamin C intakes in Indiawere given 100 mg ofvitamin C at both lunch anddinner for 60 days. Theysaw a drastic improvementin their anemia, with mostmaking a full recovery (2).

Researchers used 500 mgof vitamin C twice daily aftermeals to increasehemoglobin and serumferritin in Indian vegetarians.They concluded that vitaminC was more effective atincreasing iron status thaniron supplements (12).

The foods highest in vitaminC per typical serving areorange juice andgrapefruit juice (80 mg per cup), oranges (50 mg per small orange), broccoli (50 mg per 1/2 cup cooked,chopped), strawberries (85 mg per 1 cup of whole berries), and grapefruit (40-50 mg per 1/2 fruit). Vitamin C isalso found in other green leafy vegetables (kale, collards, Swiss chard, Brussels sprouts), bell peppers (yellow,red, and green), and cauliflower.

Polyphenols, which include tannic acid, can inhibit iron absorption, and are found in coffee, cocoa, and black,green and many herbal teas. You should avoid these foods at meals if you are trying to increase iron absorption(14). One study showed that, over four weeks, green and black tea lowered iron levels primarily in people withserum ferritin levels less than 20 g/l (15). Calcium supplements can also inhibit iron absorption if taken withmeals.

Cooking foods in cast iron pans can increase iron consumption. A 2007 study in Brazil showed that cookingtomato sauce in an iron skillet increases the amount of iron in the sauce and also increased iron status amongteen-aged and young adult lacto-ovo vegetarians (9). The authors considered it important for the food cooked tobe both acidic and water-based, such as tomato sauce.

The amino acid, L-lysine, plays a part in the absorption of iron and zinc. Among plant foods, L-lysine is onlyfound in high amounts in legumes (peanuts, beans, lentils, peas), and a vegan who doesn't eat many legumescould find themselves falling short on lysine.

Iron Deficiency in Vegetarians

The American Dietetic Association's Position Paper on Vegetarian Diets says, "Incidence of iron deficiencyanemia among vegetarians is similar to that of nonvegetarians. Although vegetarian adults have lower iron storesthan nonvegetarians, their serum ferritin levels are usually within the normal range (8)." This statement is basedon cross-sectional studies and, to my knowledge, the iron status of vegetarians or vegans on self-selected dietshas never been followed through time.

A 2004 study from Germany (11) found that 40% of premenopausal vegan and near-vegan women had low ironstores, which was four times the national average. The authors recommended that premenopausal women on avegan diet should have their iron status monitored and should consider taking iron supplements in case ofmarginal status.

I have met many ex-vegetarian women (and a few men) who claimed to become anemic after becomingvegetarian. In most cases, they did not have a doctor diagnose them but assumed they were anemic because

Page 3 of 6Iron



4/6

Table 2. Dietary Reference Intake (DRI) for Iro n

Age (years ) DRI(mg)

Veg DRI(mg)

Upper

limita

(mg)

they were tired. This could be due to numerous things, such as not eating enough calories or protein, eating toomany high-sugar foods, and possibly not getting enough sleep. However, I have heard it enough to think there isa real possibility that some women have a hard time with the lower iron absorption of plant foods, especiallywhen first becoming vegetarian.

Iron absorption may be more of a problem when people first become vegetarian because long-term studies ofvegetarian women have not shown high dropout rates. These studies usually require that someone has beenvegetarian for at least a year and anyone who gets IDA within the first few months of becoming vegetarian wouldnot be included in such a study.

Physiologically, it makes some sense that the problem would tend to show up right away or not at all, for the

following reason: The body secretes transferrin into the digestive tract when iron stores are low in order toincrease absorption of iron into the blood. If someone has been a meat-eater all her life, her body has not had aneed to manufacture as much transferrin as she might need as a vegetarian. This might cause a quick drop iniron absorption once she becomes a vegetarian. Someone's body may or may not become more efficient atproducing transferrin over time, but if she becomes anemic right away she will likely quit the diet and not give herbody the chance.

More evidence of this theory is that I have not heard of any children who were vegan from birth (and otherwisewell-nourished and living in a developed country) who developed IDA. Because vegan infants have no priorhistory of depending on heme iron, they start their lives efficiently absorbing non-heme iron and retain this abilitythroughout life.

Low Iron Stores: Not Necessarily Unhealthy

Anemia is a possible downside to lower iron absorption, but there are a few potential upsides:

Low iron stores are associated with higher glucose tolerance and might help prevent diabetes (7). High iron stores have been linked to cancer.

High iron stores have been linked to heart disease. Based on an early study, this was believed to be astrong link for a number of years. Now that more evidence has come in, the link appears to be only incases of very high iron storage levels, such as ferritin levels of greater than 200 g/l (vegans' ferritin levelsare rarely above 100 g/l). As of 2010, this theory has lost almost all ground, see:

Wood RJ . The iron-heart disease connection: is it dead or just hiding? Ageing Res Rev. 2004 J ul;3(3):355-67. (Link)

Sun Q, Ma J , Rifai N, Franco OH, Rexrode KM, Hu FB. Excessive body iron stores are notassociated with risk of coronary heart disease in women. J Nutr. 2008 Dec;138(12):2436-41. (Link)

Zegrean M. Association of body iron stores with development of cardiovascular disease in the adultpopulation: a systematic review of the literature. Can J Cardiovasc Nurs. 2009;19(1):26-32. (Link)

Hemochromatosis

Hemochromatosis is a disease of unhealthfully high iron absorption. Its most serious, homozygous form occursin about 1 in 100 blacks and 1 in 200 nonblacks. Its less serious, heterozygous form occurs in 30% of blacks and12% of nonblacks (4). Most affected people do not know they have the disease (4). People withhemochromatosis are at risk for cirrhosis (4), liver cancer (1), and other diseases. Alcoholic cirrhosis, other liverdiseases, iron-loading abnormalities, and other rare diseases can also cause iron overload (1).

Because of the possibility of hemochromatosis, men and postmenopausal women should not actively try toincrease iron absorption unless they know they have low iron stores.

Celiac Disease

Celiac disease is the cause of some cases of unexplained iron deficiency anemia (10). Celiac disease is acondition in which gluten (from wheat, barley, and rye) cause an autoimmune reaction against the intestinal cells.Often, someone has severe diarrhea, vomiting, and other problems. But other times celiac disease goesunnoticed. It occurs in about 1 in 133 people in the U.S.A. ( 10).

Proton Pump Inhibitors

Proton Pump Inhibitors (PPIs) are widely prescribed to treat gastrointestinal diseases. Research has shown thatthey can cause iron deficiency anemia (16). If you take PPIs and find that you have anemia, talk to your doctorabout a possible connection.

Recommendations

The new U.S. DRIs for iron distinguish betweenvegetarians and nonvegetarians (see Table 2). TheDRI for vegetarians was determined by increasing theregular DRI by 1.8 times (5). This is controversial

Page 4 of 6Iron



5/6

0 - 6 mos .27 .27 40

7 - 12 mos 11 11 40

1 - 3 7 12.6 40

4 - 8 10 18 40

9 - 13 8 14.4 40

boys, 14-18 11 19.8 45

girls, 14-18 15 27 45

breastfeeding,14-18

10 18 45

men 19+ 8 14.4 45

women 19-50 18 32.4 45

breastfeeding,19-50

9 16.2 45

women 50+ 8 14.4 45

pregnancy 27 48.6 45

aThe Upper Limit for iron intake is set to prevent

gastrointestinal distress rather than to prevent anypossible chronic diseases from iron overload.1

Those who engage in regular, intense exercise may need

an additional 30%.5

because the recommendations were not based onstudies of vegetarians, but rather based on vegetariandiets designed to reduce iron absorption. Such a highDRI makes it almost impossible for premenopausalwomen to meet the DRI without supplements andmany vegetarian dietitians do not think it is necessaryfor most vegetarians to get this much iron.

Iron amounts listed on a nutrition label are based on18 mg/day. For example, 25% of the Daily Value =.25x 18 mg =4.5 mg.

You do not need to worry about iron if you areotherwise healthy and eat a varied vegetarian or vegandiet. If you are concerned about iron absorption youcan take steps to increase it by removing coffee, tea,and calcium supplements from meals; adding vitaminC to meals; and increasing legume intake.

If your concerns persist, you should have a doctormeasure your iron status. If your iron stores are toolow, your doctor might suggest eating meat or takingan iron supplement. If your doctor says you should eatmeat, you might want to show him or her this article.

Anemia in meat-eaters is normally treated with largedoses of supplemental iron, not with eating more meat.Similarly, vegetarians with IDA do not need to start

eating meat but can also be treated with supplementaliron. IDA is normally treated with 100 to 200 mg/dayfor 4 to 6 months. These large amounts can causenausea, diarrhea, or constipation, and should only betaken under a doctor's care.

In some women, iron supplementation does not lead to an increase in iron stores. In one study of such women,adding L-lysine (1.5 - 2 g/day for 6 months) to iron supplementation did increase iron stores and decreased hairloss by one half.

I have a vegetarian friend who eats spinach whenever she feels anemic and she says it fixes the problem.Although feeling anemic does not mean someone is anemic, perhaps she is onto something.

References

1. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron,Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC:National Academy Press, 2001.

2. Seshadri S, Shah A, Bhade S. Haematologic response of anaemic preschool children to ascorbic acid supplementation.Hum Nutr Appl Nutr. 1985 Apr;39(2):151-4. (Link)

3. Groff J , Gropper S. Advanced Nutrition and Human Metabolism, 3rd ed. Wadsworth: 2000.

4. Mahan LK, Escott-Stump S. Krause's Food, Nutrition, & Diet Therapy, 10th ed. Philadelphia, PA: W.B. Saunders, Co.,2000.

5. Mangels R. "Update on the New DRI's" Vegetarian Nutrition Update Sum 2001;10(4):1-7.

6. Craig WJ . Iron status of vegetarians. Am J Clin Nutr. 1994 May;59(5 Suppl):1233S-1237S.

7. Hua NW, Stoohs RA, Facchini FS. Low iron status and enhanced insulin sensitivity in lacto-ovo vegetarians. Br J Nutr.2001 Oct;86(4):515-9.

8. Position of the American Dietetic Association and Dietitians of Canada: Vegetarian Diets J Am Diet Assoc. 2003

J un;103(6):748-65.

9. Quintaes KD, Farfan J A, Tomazini FM, Morgano MA, de Almeyda Hajisa NM, Neto J T. Mineral Migration and Influenceof Meal Preparation in Iron Cookware on the Iron Nutritional Status of Vegetarian Students. Ecology of Food and Nutrition.2007;46:125-141.

10. Niewinski MM. Advances in celiac disease and gluten-free diet. J Am Diet Assoc. 2008 Apr;108(4):661-72.

11. Waldmann A, Koschizke JW, Leitzmann C, Hahn A. Dietary iron intake and iron status o f German female vegans:results of th e German vegan study. Ann Nutr Metab. 2004;48(2):103-8. Epub 2004 Feb 25.

12. Sharma DC, Mathur R. Correction of anemia and iron deficiency in vegetarians by administration of ascorbic acid.Indian J Physiol Pharmacol. 1995 Oct;39(4):403-6. PMID: 8582755. (Abstract only)

13. Siegenberg D, Baynes RD, Bothwell TH, Macfarlane BJ , Lamparelli RD, Car NG, MacPhail P , Schmidt U, Tal A, MayetF. Ascorbic acid prevents the dose dependent inhibitory effects of polyphenols and phytates on nonheme-iron absorption.Am J Clin Nutr. 1991 Feb;53(2):537-41.PMID: 1989423.

Page 5 of 6Iron



6/6

14. Hurrell RF, Reddy M, Cook J D. Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages.Br J Nutr. 1999 Apr;81(4):289-95. PubMed PMID: 10999016. | link

15. Schlesier K, Khn B, Kiehntopf M, Winnefeld K, Roskos M, Bitsch R, Bhm V. Comparative evaluation of green andblack tea consumption on the iron status of omnivorous and vegetarian people. Food Research International. 2012 May;46(2):522-27. | link

16. Sarzynski E, Puttarajappa C, Xie Y , Grover M, Laird-Fick H. Association between proton pump inhibitor use andanemia: a retrospective cohort study. Dig Dis Sci. 2011 Aug;56(8):2349-53. (Abstract) | link

Page 6 of 6Iron

13 J 13h // h l h / i l /i

iron for vegans

Documents