Everything You Need to Know about Vegetarianism and the Gluten-Free Diet
By Debra Hope-Riedesel RD, LD
(Note: this article was written in 2011)
To Be or Not to Be Gluten-Free
Before we get into the Gluten-Free/Vegetarian topic, you should be aware of a few paradigm changes in current thinking regarding who should be or should not be on a gluten-free diet.
Gluten digestion is complex and in fact, none of us do a very good job of breaking it down into absorbable peptides (short amino acid chains). Add to that the latest research pointing blame on years of bio-engineering and high-protein-hybrid wheat being responsible for the increase of celiac disease and gluten sensitivity. 2 That being said, avoiding gluten without a celiac or gluten intolerance diagnosis is still a bit controversial in the mainstream medical community. There are celiac and nutrition experts who continue to think a gluten-free diet is dangerous or unhealthy for those without a diagnosis of celiac disease. Proof of this attitude aired recently on ABC’s Nightline Nov. 4th, in an interview with Dr. Peter Green of Columbia University Celiac Center.
Having a “celiac diagnosis” before going on a gluten-free diet is no longer essential, according to Alessio Fasano MD, one of the top celiac researchers in the world, who recently told an audience of registered dietitians to “have an open mind” during an educational session at the ADA Food and Nutrition Conference in Boston. “If someone tests negative for celiac disease, they may still be gluten sensitive and improve on a gluten-free diet.” This is something many non-celiac gluten sensitive people, without a gold standard, biopsy celiac diagnosis, have been waiting to hear from Fasano for years.
Going gluten-free and then getting a diagnosis? Here’s the catch-22. Once someone eliminates gluten from their diet, the current blood tests lose their effectiveness to detect antibodies associated with celiac or non-celiac gluten sensitivity (NCGS). If someone eliminates gluten from their diet as an experiment and starts to feel noticeably better, they may then run the risk of feeling lousy again for weeks from reintroducing gluten back into their diet before their physician could confirm a gluten intolerance. The prudent thing to do is to screen first for celiac before removing gluten from the diet, but again not all gluten intolerance is celiac disease. Many times people have celiac or non-celiac gluten sensitivity for years without even knowing they have it, current research shows that 70% of those who are celiac do not present with GI distress as in the classic type of celiac.
It’s been my experience that someone without a solid diagnosis may question the diet during times of weakness and continue to eat gluten occasionally, keeping the damaging immune or autoimmune response going. The recent changes in diagnostic criteria may help in getting a celiac diagnosis however non-celiac gluten sensitivity still remains elusive to most gastroenterologists. There is new hope of a more sensitive mainstream test becoming available sooner rather than later for those with non-celiac gluten sensitivity due to a $45 million dollar donation to the Center for Celiac Research at the University of Maryland. Many, who question their tolerance of gluten, have found confirmation through an elimination diet or through alternative and integrative medicine practitioner. Alternative and Integrative medical practitioners acknowledge and have been treating NCGS for years, prior to research confirming it as a separate and distinct disorder.
AND (formerly the ADA) Position on Vegetarianism:
“It is the position of the Academy of Nutrition and Dietetics, formerly known as the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life-cycle including pregnancy, lactation, infancy, childhood and adolescence and for athletes.” 3
Planning a gluten-free and vegan lifestyle may add a few extra concerns but still manageable, especially with the help of your physician and a skilled registered dietitian. A vegetarian diet is actually quite compatible with the gluten-free diet. The focus on fruits, vegetables, nuts, seeds, beans and high protein GF grains make up for some inadequacies found in a typical GF diet focused on highly processed pre-packaged foods and refined starches. Inadequacies of a gluten-free diet are: folate, fiber, magnesium, and vitamins A, C, K, and E.
What are the different kinds of Vegetarians?
By definition: Vegetarianism is way of life based entirely on a plant-based diet that includes fruits, vegetables, grains, nuts & seeds, with or without dairy products and eggs. A vegetarian does not eat meat, including red meat, game, poultry, fish, or shellfish.
“ Veganism is a philosophy and lifestyle whose adherents seek to exclude the use of animals for food, clothing, or any other purpose. Vegans endeavor not to use or consume animal products of any kind. The most common reasons for becoming a vegan are human health, ethical commitment or moral conviction concerning animal rights or welfare, the environment, and spiritual or religious concerns. Of particular concern to many vegans are the practices involved in factory farming and animal testing, and the intensive use of land and other resources for animal farming.” 4
A Lacto-vegetarian also consumes dairy.
An Ovo-vegetarian consumes eggs but not dairy.
An Ovo-lacto-vegetarian consumes eggs and dairy.
A Semi-Vegetarian may be referred to as a flexitarian, in order for the term vegetarian to remain true to the meaning. Flexitarians consume meat, dairy, eggs, and fish on occasion but maintains a plant based diet the majority of the time.
While ovo-lacto vegetarians have an easier time getting enough high biological value protein, B12, iron, zinc, calcium, DHA and EPA Omega 3’s through eggs and dairy, the vegan may find it more difficult without help from supplements.
Add a gluten-free lifestyle into the mix and many foods normally fortified with thiamin, riboflavin, niacin, vitamin B6, & vitamin D become limited and in this case these nutrients should also be added to the list of nutrient concerns. This does not take into consideration malabsorption issues that may still linger in someone with celiac disease, gluten sensitivity, or co-morbidities of IBD and other food sensitivities not yet discovered or possibly developed in the future. If you are still on board to become a gluten-free vegan, learning how to plan your meals wisely and asking for B12, folate, iron and vitamin D testing during regular check-ups may be a good idea. (B12, B6, folate, iron, zinc and vitamin D along with calcium and magnesium deficiencies are associated with celiac)
Nutrients of Concern
Protein– Inadequate or poor quality protein is typically thought of as the most common concern in vegetarian diets, but can be met without a problem. Gluten the major protein in wheat, rye and barley just happens to also be one of the higher quality vegetarian proteins available to those who can tolerate it. Seitan, the vegetarian “faux meat” is made entirely of wheat gluten, with a few spices thrown in, and has been a prime vegetarian protein for years. Right now, if you are gluten intolerant, you are probably gasping for breath at the idea that people would intentionally eat straight gluten. Yes, they did and still do. Is it a good idea? I’m weighing in on the negative more and more these days, especially if there’s autoimmune disease in the family medical history. Regarding Comment 13 (yes, there is evidence of increased celiac and NCGS rates due to eating more gluten see #2 in references)
There are a few superior and a few very good high-protein GF/vegetarian sources that should be staples in the GF/vegetarian diet. They include: soy, quinoa, amaranth, sorghum, buckwheat, MontinaTM (Indian ricegrass), teff, nuts, and legumes (beans). Another grass seed flour, TimtanaTM ,made from Timothy grass contains a good amount protein but not widely known or distributed yet. You can find more information about it at www.montanaglutenfree.com
If you can tolerate verified GF Oats (after being GF for 6 months) then by all means include up to 2/3- 1 cup a day. Not all Celiacs may be able to tolerate oats so it’s best to pay close attention to GI symptoms and talk with your gastroenterologist. The jury is still out on oat limits for the non-celiac gluten sensitivity (NCGS) individual. Oats are a good source of protein, thiamin (B1) and soluble fiber.
Quinoa, amaranth, buckwheat and soy are considered especially good protein sources because they contain all 8 essential amino acids. These should go to the top of any vegetarian’s shopping list. They also contain some other important nutrients like thiamin, riboflavin, B6, niacin, magnesium, iron, zinc and fiber. Essential amino acids are essential because the body cannot synthesize them, making it essential to include them in one’s diet. The 8 essential AA’s are: phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, leucine, and lysine. Quinoa, amaranth and soy have higher levels of lysine than buckwheat. Adding a legume during the day when buckwheat is on the menu boost the lysine. Hemp seeds are also a good plant protein and are becoming more available here in the US but due to its association with cannabis may not be familiar as a food seed. Products coming into the US from Canada where hemp is legal to grow are tested to be 100% THC free.
For adequate protein the general rule is 10-15% of total calories or .8 grams per kg of weight. You may also use .4 grams per pound. An easier way to figure this out is to take your weight, divide it in half and subtract 10. This will give an approximation of the amount of protein that you need.
As an example: A person who weighs 150lbs divided by 2 minus 10 = 65 grams of protein a day. These recommendations are not necessarily enough for someone under stress of an illness. For a recovering celiac or recently diagnosed non-celiac gluten sensitive individual I would suggest adding more protein to the diet for tissue repair in the way of verified GF whole foods as a first choice rather than supplements or individual amino acids.
If allergic or sensitive to soy and/or legumes, a supplemental rice or hemp protein powder may be a good idea if following a vegan diet. New GF vegan protein powders are coming on to the market. Keep in mind protein powders are sold as “supplements” and do not fall under the same FDA allergen labeling laws. See frequently asked question about FALCPA (This may change with new GF labeling law) These products will most likely not be verified and may actually say “gluten-free” on the label. If you are gluten intolerant and would like to try any of these supplemental protein powders, call the manufacturer and ask about processing practices or how they test for gluten parts-per-million (ppm). Check independent product reviews like Amazon.com or other celiac websites for possible cross-contamination reactions from members who may have had a problem with the product.
How much protein in GF grain?
Soy beans, Edamame ½ cup = 14 grams Pro
Amaranth flour ½ cup = 10 grams Pro *
Buckwheat groats (roasted) ½ cup = 9 grams Pro
Quinoa ¼ cup dry ½ cup = 6 grams of Pro
Sorghum flour ½ cup = 7.5 grams Pro *
Montina flour ½ cup = 13 grams Pro*
Timtana flour ½ cup = 10 grams Pro*
Teff flour ½ cup= 8 grams Pro*
Verified Pure Oats ½ cup dry = 7 grams Pro
Brown rice, long grain ½ cup cooked =2.5 grams Pro (white rice ½ cup cooked = 2 grams Pro)
Yellow corn ½ cup cooked = 2.3 grams Pro
Brown rice protein powder 2 Tablespoons = 15 grams Pro (suggested supplement)(source: USDA nutrition data base)5
*Grain will likely be combined with 100% starch flour in baking resulting in lower total protein per serving. Example: 1 slice of Udi’s bread made from tapioca, brown rice, potato starch, teff, and egg contains 1.5g pro, serving size is 2 slices for a total of 3 grams of protein. In comparison, regular wheat bread contains 3 grams of pro in 1 slice of bread. The majority of commercially made GF breads contain egg and many times dairy, adding to total protein but is off limits to vegans or anyone with multiple food intolerances.
Other GF grain concerns:
Soy, a vegetarian protein powerhouse, also happens to be one of the top 8 food allergens. It’s not uncommon to see multiple food sensitivities and allergies in the same person. There is limited research regarding IgA, and IgG antibody development or what may be referred to as a delayed allergy to soy. We can however be confident that any undigested protein may have access through the intestinal tight junction when damaged, something common in celiac disease, leaky gut or a hyper- permeable gut, initiating a possible immune mediated response.6
Autoimmune thyroid disease is also common among individuals with celiac and gluten sensitivity. People on thyroid medication may want to avoid eating soy and taking their medication at the same time. Soy may inhibit the medication absorption, but the same can be said for high fiber, iron, calcium and antacids. Two hours between ingestion of soy and medication, vitamins and minerals may be prudent if you are taking thyroid medication.
Cross Contamination in Naturally Gluten-Free Grains
An important issue highlighted recently in a pilot study (Thompson, T. June, 2010) confirmed a long standing concern regarding wide spread cross-contamination of naturally gluten-free grains. Increasing consumption of untested naturally GF grains may also increase unintentional gluten consumption in those who rely on GF grains for protein needs. Making sure grains come from designated GF facilities with pristine processing practices is highly recommended.
Vitamin B12 also known as cobalamin, is a water soluble vitamin with involvement in every cell of the human body because of its role in DNA synthesis. It also has key roles in the normal functioning of the brain and nervous system as well as the formation of red blood cells. Vitamin B-12 is the only water soluble vitamin that is stored at high levels in the liver.
The best sources of B12 are animal sources, which is why B12 deficiency is of concern in vegans. Dairy and eggs are also very good sources of B12 for those GF/vegetarians who can tolerate dairy and eggs.
According to the Vegetarian Resource Group; “ Non-animal sources of B12 include Red Star Vegetarian Support Formula or T-6635+ nutritional yeast (a little less than 1 Tablespoon supplies the adult RDA), and vitamin B12 fortified soymilk. It is especially important for pregnant and lactating women, infants, and children to have reliable sources of vitamin B12 in their diets.” (http://www.vrg.org/)
Individuals with co-morbidities of celiac, or gluten sensitive individuals with IBD (Crohn’s, ulcerative colitis) may also have a sensitive to dietary yeast.7 Nutritional yeast may not be the best recommendation as a vitamin B12 supplement.
Individuals diagnosed with Celiac disease, non-celiac gluten sensitivity with malabsorption and hypo or achlorhydria (low stomach acid) issues may have difficulty not only absorbing B-12 but may be suffering from low B12 levels to begin with. It is very important before starting a vegetarian diet of any kind to have B12 levels tested and monitored on a regular basis. Individuals with pernicious anemia, also autoimmune, may require regular B12 injections. Sublingual B12 may also be recommended in those with residual gastro-intestinal damage.
Studies have shown that B12 deficiency can lead to abnormal neurologic and psychiatric symptoms. Symptoms may include: ataxia, muscle weakness, spasticity, low blood pressure, vision problems, dementia, depression, mood disturbances and psychoses. Researchers report that these symptoms may occur when vitamin B12 levels are just slightly lower than normal which may still be considerably above the levels normally associated with megaloblastic anemia.
Other individuals at risk for vitamin B12 deficiency include: strict vegetarians, elderly people, breastfed infants, and people with associated autoimmune conditions such as Hashimotos Thyroiditis, Graves’ disease and Vitiligo (patchy discoloration of the skin). Vitamin B12 requirements increase with pregnancy, thyrotoxicosis, hemolytic anemia, hemorrhage, malignancy and with liver or kidney disease.
Table 1: Recommended Dietary Allowances (RDAs) for Vitamin B12
* Adequate Intake 0-6months source http://ods.od.nih.gov/factsheets/vitaminb12/
Iron is an essential mineral in hemoglobin and is responsible for attracting oxygen molecules out of the lungs into the blood cells that then carry it to body tissue. If you are anemic or short on iron, your blood cells become smaller (microcytic) and you feel tired all the time basically from a lack of oxygen at the cellular level.
There are two kinds of iron, heme and non-heme, hence the term hemoglobin. Heme iron is found in meat. Heme iron is considered a higher quality iron source because it’s more available for absorption in the body. The body however can still squeeze non-heme iron out of sources like:
Soy Tofu- firm, ½ cup (6.6mg iron)
Pumpkin seeds, ¼ cup (5.2mg iron)
Quinoa, dry, ¼ cup (3.9mg iron)
Amaranth, dry ¼ cup (3.7mg iron)
Lentils, cooked ½ cup (3.3mg iron)
Teff, dry ¼ cup (3.0mg iron)
Chickpeas cooked ½ cup (2.4mg iron)
Baked potato w/skin 1 med (2.3mg iron)
Black strap molasses 2Tbs (1.88mg iron)
Spinach raw, 1 cup (.81mg iron)
Adding foods high in vitamin C helps non-heme iron absorption by 6 fold. The perfect vegetarian food a.k.a. broccoli, contains good levels of vitamin C and a small amount of iron, add a few pumpkin seeds to any green salad or vegetable high in C will help. Combining tomato sauce and beans or adding mandarin orange sections to a spinach salad makes perfect sense and a tasty meal. For more information on vegetarian iron source foods check out The Vegetarian Resource Group’s website http://www.vrg.org/nutrition/iron.htm
DRI, RDA Iron requirements:
Children 1-3 (7mg/per day) Children 4-8 10mg/per day)
Males 9-13 (8mg/per day) Males 14-18 (11mg/per day)
Males 19-70 (8mg/per day)
Females 9-13 (8mg/per day) Females 14-18 (15mg/per day)
Females 19-50 (18mg/per day) Females 50-70 (8mg/per day)
(Note: IOM DRI/RDA estimates are based on 75% heme iron. If strict vegan, the RDA is 1.8 times higher than those for non-vegetarians)
Iron is also one of the many commonly poorly absorbed nutrients in undiagnosed celiac disease, and non-celiac gluten sensitivity with inflammation. Taking an iron supplement may help but can cause nausea and be hard on an already sensitive stomach. Taking large amounts of iron may add to constipation. It is not uncommon to see small intestinal bacterial overgrowth (SIBO) in gluten intolerant individuals due to mal-digestion of carbohydrates. Increased iron supplementation in iron anemia deficiency may also increase bacterial naturally found in the large intestine allowing movement into the small intestine. Bacteria flourish in iron enriched environments. 8
Anyone with unexplained iron deficiency anemia should always be screened for celiac and gluten sensitivity. Iron stores and status improves over time on a gluten-free diet but it’s always prudent to monitor fairly often if sharing a household with gluten eaters. Constant risk of cross contamination issues may interrupt normal iron absorption putting GF vegans at a risk of iron deficiency anemia .
Calcium is one of the most important minerals in the body. It’s not only important for bone and teeth health but muscle contractions, nerve signaling and blood coagulation. Calcium plays a role in approximately 300 chemical reactions in metabolism so it’s important to keep a good daily intake. Dairy has always been the standard calcium source, but for those who cannot tolerate it or those who choose not to consume dairy, it’s not the end of the world. The good news for vegans and the dairy adverse, calcium is also found in many great vegetarian sources such as fortified non-dairy milks and yogurts like soy, almond, rice, coconut, and hemp. It seems like food manufacturers are putting extra calcium in just about everything including fruit juices, bottled vitamin water, margarines, peanut butters, and fruit spreads just to name a few.
Vegetarian foods high in calcium include broccoli, bok choy, collards, kale, tofu, black strap molasses, beans and almonds. There’s also fortified coconut milk beverage, coconut water, So Delicious cultured yogurt from coconut milk or soy and Turtle Mountain’s Purely Decadent dairy-free frozen desserts. More and more dairy-free cheese products fortified with calcium are becoming more available in the supermarkets. Be sure and read the label on all dairy-free products to make sure they’re calcium fortified and vegan, some rice milk cheese add casein (dairy) to their product to get a smoother texture.
Adult recommendations are 1,000-1,200mg a day. Teens or 9-18 years old require 1,3000mg/day
Calcium is commonly mal-absorbed in celiac disease and non-celiac gluten sensitivity. Malabsorption along with severe vitamin D deficiency compounds the problem not only for calcium but for many minerals primarily absorbed in the upper GI tract. Osteopenia and osteoporosis may be a problem in newly diagnosed gluten intolerant individuals. Calcium, magnesium, phosphorous, and other minerals need vitamin D for proper absorption. Calcium supplementation has been known to worsen constipation in already susceptible individuals, adding a small amount of magnesium may help.
Vegetarian diets may also be a bit higher in oxalates bond to calcium which inhibits calcium absorption. Oxalates and calcium may form into crystals in the right environment injuring tissue in the kidneys and bladder. If you have a family history of oxalate kidney stones you may want to consider reducing high oxalate containing foods. Kidney stone formers will want to make sure they work with their physicians and a registered dietitian on a low oxalate diet plan that includes low-oxalate adequate greens. For a list of high oxalate foods see: http://www.upmc.com/healthatoz/patienteducation/documents/lowoxalatediet.pdf
We’re learning more about the importance of sufficient levels of vitamin D, also known as the sunshine vitamin. Vitamin D plays a major role in mineral absorption but may have a role in preventing autoimmune disease, cancer and the common cold. About 2,000 genes are affected by 1-25(OH)D. (Holick, E.Cadherin.) The active form of vitamin D, 1,25,(OH) D is actually a hormone. Every tissue and cell in the body has vitamin D receptors (VDR).
There are few foods containing vitamin D naturally and of course most are fortified animal and fish sources. Getting outside into the sun for 10-30 minutes a day becomes more important if you are vegan. Anyone with an autoimmune disease or who lives in the upper latitudes of the US and Canada should be checked semi-annually for vitamin D deficiency with a goal of >30ng/ml of 25(OH) D. The new RDA/DRI for vitamin D was recently raised (Nov. 30th) from 400 IU/day to 600 IU/day for adults 18-70 and 800 IU/day 70+ with an upper limit set at 4,000 IU, but is still considered low by several prominent vitamin D researchers. 9 The following vitamin D recommendations are per Dr. Michael Holick (FNCE 2010)
Adequate Intake (AI)
0-1 years 400-1,000 IU/D
1-12 years 1,000-2,000 IU/D
13+ years 1,500-2,000 IU/D
Obesity 2-3 times more
Safe Upper Intake (UI)
0-1 years 2,000 IU/D
1-12 years 5,000 IU/D
13+ years 10,000 IU/D
There are many forms of vitamin D but the two best known dietary forms are D2 (ergocalciferol) the vegetarian and prescription form and D3 (cholecalciferol) usually from a fish source. Vegans will need to rely on D2 ergocalciferol on a daily basis during the winter months in higher latitudes in order to keep their D levels up. According to Dr. Holick, vitamin D made in the skin lasts twice as long dietary vitamin D. For more information on vitamin D, check out http://www.vitamindcouncil.org/
Contraindication to vitamin D supplementation is a diagnosis of hypercalcemia and renal disease. Patients with renal disease will need to be monitored by their physician regularly for active vitamin D. Renal patients have difficulty converting 25(OH)D to the active form.
Omega 3’s ALA, DHA, & EPA
Much has been written about the long chain omega 3 essential fatty acid, α-linolenic acid (ALA ), Docosahexaenoic acid (DHA), and Eicosapentaenoic acid, (EPA). They are called essential fatty acids because we cannot synthesize them and must get them through our diet. Current research indicates the fatty acids DHA and EPA may be much more important than thought for neuron development, ophthalmic health, depression, reduction of the inflammation response and heart disease prevention.
Dietary alpha-linolenic acid (ALA) is the plant based essential fatty acid. Excellent sources are found in flax seed, chia seed, hemp seed, walnuts and canola. A new GM soybean produces large amounts of a non-essential omega 3 fatty acid, called Stearidonic acid (SDA) which is believed to convert easier to EPA. (Soyconnection.com) Most research on ALA shows the average conversion rates from ALA to DHA is only 5% and similar poor conversion rates to EPA. Some scientists believe this is inadequate to attain efficacious tissue levels of EPA and DHA. Microalgae, is the only acceptable vegan DHA source and can be found in supplemental forms in many health food stores. If you are planning a vegan diet this is one supplement you will want to consider daily.
More information about Omega 3’s can be found at the Office of Dietary Supplements: http://ods.od.nih.gov/factsheets/Omega3FattyAcidsandHealth/
Dietary Reference intake (DRI) Adequate Intake(AI) for ALA
ALA (AI) is 1.6g/d men, 1.1g/d women, Vegans should probably increase this amount to 2-3x’s due to poor conversion rates to DHA or make sure they take additional microalgae DHA capsule. There is no DRI for DHA or EPA but studies suggest the following DHA, EPA recommendation:
Adults DHA & EPA 500mg/day (Listed separately on fish oil) 10
Zinc is a widely available mineral found in foods including meat, poultry, fortified cereals, beans, nuts and dairy products. Most people don’t have a problem getting enough zinc in their diet unless they have digestive issues such as Celiac, NCGS, IBD (Crohn’s, Ulcerative Colitis), have had gastric bypass surgery or chose a vegetarian or vegan diet. Zinc absorption is lower for those consuming vegetarian diets than for those eating non-vegetarian diets. It has been suggested that the zinc requirement for vegetarian is approximately 2 fold of the current DRI/RDA
Zinc deficiencies can lead to immune impairment, appetite loss, hair loss, loss of the ability to taste, slow sexual development in children and impotency in men.
GF/Vegetarian sources of Zinc include:
Pumpkin/squash seeds ¼ cup = 2.6mg
Wild rice, dry, ¼ cup =2.3mg
Navy beans (cooked) ½ cup = 2.3mg
Teff dry ¼ cup = 2.2mg
Cashews ¼ cup = 1.9mg
Sunflower seeds ¼ cup =1.8mg
Amaranth dry ¼ cup = 1.5mg
Oat bran raw ½ cup = 1.46mg
Quinoa dry ¼ cup = 1.4mg
Garbanzo beans(cooked) ½ cup =1.3mg
Almonds ¼ cup = 1.2mg
Cornmeal ½ cup = 1.1mg
Buckwheat dry ¼ cup = 1.0mg
(source: USDA nutrition database- zinc content of select foods)
DRI for Zinc
Children 1-3 (3mg/d) children 4-6 (5mg/d)
Males 9-13 (8mg/d) Males 14-70 (11mg/d)
Females 9-13 (8mg/d) Females 14-18 (9mg/d)
Females 19->70 (8mg/d)
Disclosures: I have tremendous respect for those with the dedication to adhere to a lifestyle standard that supports the rights of all animals and the environment, although I am not vegetarian myself. A Vegan diet can be tailored to meet nutritional needs when also confronted with malabsorption issues such as celiac disease or non-celiac gluten sensitivity. If you are considering becoming vegan or vegetarian, getting familiar with all dietary pitfalls is important. Consulting with your gastroenterologist and a skilled registered dietitian in both the gluten-free and vegetarian diet is always recommended.
2) Van den Broeck HC, de Jong HC, Salentijn EM, Dekking L, Bosch D, Hamer RJ, Gilissen LJ, van der Meer IM, Smulders MJ. Presence of celiac disease epitopes in modern and old hexaploid wheat varieties: wheat breeding may have contributed to increased prevalence of celiac disease. Theor Appl Genet. 2010 Nov;121(8):1527-39. Epub 2010 Jul 28
3) ADA Press Release, July 1, 2009 Appropriate Planned Vegetarian Diets Are Healthful, May Help in Disease Prevention and Treatment, Says American Dietetic Association http://www.eatright.org/Media/content.aspx?id=1233
4) Wikipedia: http://en.wikipedia.org/wiki/Vegetarianism
5) USDA Nutrition Database http://www.nal.usda.gov/fnic/foodcomp/search/
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7) Benjamin J, Makharia GK, Joshi YK. Association between intestinal permeability and anti-Saccharomyces cerevisiae antibodies in patients with Crohn’s disease; Inflamm Bowel Dis. 2008 Nov;14(11):1610-1
8)Excess Iron Intakes Increases Risk of Intestinal Infections, Study Suggests, Ohio State Research http://researchnews.osu.edu/archive/iron.htm
9) Heaney, RP, Holick, MF. Why the IOM recommendations are deficient. J Bone Miner Res. 2011 Jan 4.
10) Kris-Etherton PM, Grieger JA, Etherton TD. Dietary reference intakes for DHA and EPA. Prostaglandins Leukot Essent Fatty Acids. 2009 Aug-Sep;81(2-3):99-104.