Generally Eclectic

Making It Work: The Science of a Safe Vegetarian Diet

Below are a sample of abstracts from PubMed over the period 2007 to March 2013 on the health and safety of a "vegetarian" diet. Key concerns include bone loss, vitamin B12 deficiency and vitamin D deficiency, and renal functions. The key conclusions is that a well-planned "vegetarian" diet that manages these potential problems can be safe.


  1. Diet-dependent net endogenous acid load of vegan diets in relation to food groups and bone health-related nutrients: results from the German Vegan Study by Strahle A, Waldmann A, Koschizke J, Leitzmann C, Hahn A in Ann Nutr Metab. 2011;59(2-4):117-26. "...We investigated the potential renal acid load (PRAL) and the estimated diet-dependent net acid load (net endogenous acid production, NEAP) in adult vegans and evaluated the relationships between NEAP, food groups and intake of bone health-related nutrients...Mean daily intakes of phosphorus, potassium, sodium, magnesium and vitamin C were above, and vitamin D and calcium below Dietary Reference Intake (DRI)...(T)he diet in the GVS was characterized by a nearly neutral NEAP...It can be hypothesized that vegan diets do not affect acid-base homeostasis.
  2. Vegetarianism, bone loss, fracture and vitamin D: a longitudinal study in Asian vegans and non-vegans by Ho-Pham LT, Vu BQ, Lai TQ, Nguyen ND, Nguyen TV in Eur J Clin Nutr. 2012 Jan;66(1):75-82. "The aim of this study was to examine the association between veganism and bone loss in postmenopausal women...Vegan diet did not have adverse effect on bone loss and fracture. Corticosteroid use and high intakes of animal protein and animal lipid were negatively associated with bone loss."
  3. Health aspects, nutrition and physical characteristics in matched samples of institutionalized vegetarian and non-vegetarian elderly (> 65yrs) by Deriemaeker P, Aerenhouts D, De Ridder D, Hebbelinck M, Clarys P in Nutr Metab (Lond). 2011 Jun 14;8(1):37. "It was the purpose of the present study to compare nutritional and physical characteristics in matched samples of institutionalized vegetarian (V) and non-vegetarian (NV) elderly...Generally, our results show a similar profile for V and NV concerning dietary intake, blood values, and physical characteristics...This study indicates that a vegetarian lifestyle has no negative impact on the health status at older age.
  4. A vegetarian dietary pattern as a nutrient-dense approach to weight management: an analysis of the national health and nutrition examination survey 1999-2004 by Farmer B, Larson BT, Fulgoni VL 3rd, Rainville AJ, Liepa GU in J Am Diet Assoc. 2011 Jun;111(6):819-27. "...To compare dietary quality of vegetarians, nonvegetarians, and dieters, and to test the hypothesis that a vegetarian diet would not compromise nutrient intake when used to manage body weight...Mean intakes of fiber, vitamins A, C, and E, thiamin, riboflavin, folate, calcium, magnesium, and iron were higher for all vegetarians than for all nonvegetarians. Although vegetarian intakes of vitamin E, vitamin A, and magnesium exceeded that of nonvegetarians ..., both groups had intakes that were less than desired. ...These findings suggest that vegetarian diets are nutrient dense, consistent with dietary guidelines, and could be recommended for weight management without compromising diet quality.
  5. Iodine status and thyroid function of Boston-area vegetarians and vegans by Leung AM, Lamar A, He X, Braverman LE, Pearce EN in J Clin Endocrinol Metab. 2011 Aug;96(8):E1303-7. "The objective of the study was to assess the iodine status and thyroid function of U.S. vegetarians ... and vegans ... and whether these may be affected by environmental perchlorate and thiocyanate exposures...U.S. vegetarians are iodine sufficient. U.S. vegans may be at risk for low iodine intake, and vegan women of child-bearing age should supplement with ... iodine daily. Environmental perchlorate and thiocyanate exposures are not associated with thyroid dysfunction in these groups.
  6. Nutrition concerns and health effects of vegetarian diets by Craig WJ in Nutr Clin Pract. 2010 Dec;25(6):613-20. "...When a vegetarian diet is appropriately planned and includes fortified foods, it can be nutritionally adequate for adults and children and can promote health and lower the risk of major chronic diseases. The nutrients of concern in the diet of vegetarians include vitamin B(12), vitamin D, Omega-3 fatty acids, calcium, iron, and zinc...(V)egetarians typically have lower body mass index, serum total and low-density lipoprotein cholesterol levels, and blood pressure; reduced rates of death from ischemic heart disease; and decreased incidence of hypertension, stroke, type 2 diabetes, and certain cancers than do nonvegetarians."
  7. The influence of vegan diet on bone mineral density and biochemical bone turnover markers by Ambroszkiewicz J, Klemarczyk W, Gajewska J, Chelchowska M, Franek E, Laskowska-Klita T in Pediatr Endocrinol Diabetes Metab. 2010;16(3):201-4. "...We examined a family on vegan diet which consisted of parents and two children. ...Our results suggest that an inadequate dietary intake of calcium and vitamin D may impair the bone turnover rate and cause a decrease in bone mineral density in vegans."
  8. Comparison of renal function and other health outcomes in vegetarians versus omnivores in Taiwan by Lin CK, Lin DJ, Yen CH, Chen SC, Chen CC, Wang TY, Chou MC, Chang HR, Lee MC in J Health Popul Nutr. 2010 Oct;28(5):470-5. "...The study explored the effects of both the diets (diet of plant origin, and diet of plant and animal origin) on renal functions. The study subjects included 102 Buddhist nun vegetarians and an equal number of matched control group (omnivores)...There was no difference in the renal functions between the two groups. However, systolic blood pressure, blood urea nitrogen, serum sodium, glucose, cholesterol levels, and urinary specific gravity were lower in the vegetarian group."
  9. Plasma concentrations of 25-hydroxyvitamin D in meat eaters, fish eaters, vegetarians and vegans: results from the EPIC-Oxford study by Crowe FL, Steur M, Allen NE, Appleby PN, Travis RC, Key TJ in Public Health Nutr. 2011 Feb;14(2):340-6. "Vegetarians and vegans exclude certain food sources of vitamin D from their diet, but it is not clear to what extent this affects plasma concentrations of 25-hydroxyvitamin D (25(OH)D). The objective was to investigate differences in vitamin D intake and plasma concentrations of 25(OH)D among meat eaters, fish eaters, vegetarians and vegans...Plasma 25(OH)D concentrations were lower in vegetarians and vegans than in meat and fish eaters; diet is an important determinant of plasma 25(OH)D in this British population."
  10. Vegetarian diets are associated with healthy mood states: a cross-sectional study in seventh day adventist adults by Beezhold BL, Johnston CS, Daigle DR in Nutr J. 2010 Jun 1;9:26. "...We examined associations between mood state and polyunsaturated fatty acid intake as a result of adherence to a vegetarian or omnivorous diet...Vegetarians ... reported significantly less negative emotion than omnivores... VEG reported significantly lower mean intakes of EPA ..., as well as the omega-6 fatty acid, arachidonic acid ..., and reported higher mean intakes of shorter-chain alpha-linolenic acid ... and linoleic acid...(P)articipants with low intakes of EPA, DHA, and AA and high intakes of ALA and LA had better mood...The vegetarian diet profile does not appear to adversely affect mood despite low intake of long-chain omega-3 fatty acids."
  11. Nutritional status of Flemish vegetarians compared with non-vegetarians: a matched samples study by Deriemaeker P, Alewaeters K, Hebbelinck M, Lefevre J, Philippaerts R, Clarys P in Nutrients. 2010 Jul;2(7):770-80. "The present study compares the nutritional status of vegetarian (V) with non-vegetarian (NV) subjects...Our results clearly indicate that a vegetarian diet can be adequate to sustain the nutritional demands to at least the same degree as that of omnivores. The intakes of the V subjects were closer to the recommendations for a healthy diet when compared to a group of well matched NV subjects."
  12. Haematological, biochemical and bone density parameters in vegetarians and non-vegetarians by Sambol SZ, Stimac D, Orlic ZC, Guina T in West Indian Med J. 2009 Dec;58(6):512-7. "The objective is to determine any possible differences between haematological, biochemical and bone mineral density in vegetarians (vegans and lacto-ovovegetarians) and non-vegetarians...The results showed that lacto-ovovegetarians had statistically significantly higher red blood cell counts and haematocrit values than non-vegetarians. Vegans also had higher haematocrit values than non-vegetarians. Statistically significant differences were found between iron plasma levels in the examined groups. Iron levels were lower in non-vegetarians than in vegans and lacto-ovovegetarians. Non-vegetarians had much higher levels of cholesterol, triglycerides and LDL than the other two groups, but there were no differences found between same values in vegans and lacto-ovovegetarians...A well planned and balanced vegetarian diet, with avoidance of risk factors, does not result in abnormalities in laboratory tests and bone status parameters."
  13. Enhanced bone metabolism in vegetarians--the role of vitamin B12 deficiency by Herrmann W, Obeid R, Schorr H, H?bner U, Geisel J, Sand-Hill M, Ali N, Herrmann M in Clin Chem Lab Med. 2009;47(11):1381-7. "...Vitamin B12 deficiency and bone fractures are common in vegetarians. However, a direct relationship between vitamin B12 status and bone metabolism in vegetarians has not been tested sufficiently...Low vitamin B12 status is related to increased bone turnover in vegetarians which is independent from vitamin D status."
  14. >The association between high plasma homocysteine levels and lower bone mineral density in Slovak women: the impact of vegetarian diet by Krivos?kov? Z, Krajcovicov?-Kudl?ckov? M, Spustov? V, Stef?kov? K, Valachovicov? M, Blaz?cek P, Nemcov? T in Eur J Nutr. 2010 Apr;49(3):147-53. "...To assess the possible impact of a vegetarian diet on bone mineral density in cohort of Slovak vegetarian women...Vegetarians had a significantly lower weight ..., and homocysteine...Vitamin B(12) was significantly higher in nonvegetarians... No differences were observed in folate levels...Homocysteine is one of the predictors of bone mineral density...In healthy adults, homocysteine levels are dependent on age as well as on nutritional habits. Thus, elderly women on a vegetarian diet seem to be at higher risk of osteoporosis development than nonvegetarian women."
  15. Effect of vegetarian diets on bone mineral density: a Bayesian meta-analysis by Ho-Pham LT, Nguyen ND, Nguyen TV in Am J Clin Nutr. 2009 Oct;90(4):943-50. "...The aim of this study was to estimate the effect of vegetarian diets on BMD (bone mineral density) by using a meta-analytic approach...The results suggest that vegetarian diets, particularly vegan diets, are associated with lower BMD, but the magnitude of the association is clinically insignificant."
  16. DHA status of vegetarians by Sanders TA in Prostaglandins Leukot Essent Fatty Acids 2009 Aug-Sep;81(2-3):137-41. "...To review DHA status in vegetarians and vegans...Dietary analyses show that vegan diets are devoid of DHA and vegetarian diets that included dairy food and eggs only provide about 0.02 g DHA/d. Vegetarian and especially vegan diets supply more linoleic acid ... than omnivore diets. The intake of alpha-linolenic acid ... also tends to be similar or greater but depends on culinary oils used. The proportions of DHA in plasma, blood cells, breast milk, and tissues are substantially lower in vegans and vegetarians compared with omnivores. The lower proportions of DHA are accompanied by correspondingly higher proportions of the long-chain derivatives of linoleic acid, indicating that the capacity to synthesize long-chain polyunsaturated fatty acids is not limited. Short-term dietary supplementation with alpha-linolenic acid ... does not increase the proportion of DHA in blood lipids...There is no evidence of adverse effects on health or cognitive function with lower DHA intake in vegetarians..."
  17. Veganism, bone mineral density, and body composition: a study in Buddhist nuns by Ho-Pham LT, Nguyen PL, Le TT, Doan TA, Tran NT, Le TA, Nguyen TV in Osteoporos Int. 2009 Dec;20(12):2087-93. "...(A)lthough vegans had lower dietary calcium and protein intakes than omnivores, veganism did not have adverse effect on bone mineral density and did not alter body composition....(A)lthough vegans have much lower intakes of dietary calcium and protein than omnivores, veganism does not have adverse effect on bone mineral density and does not alter body composition.
  18. Serum 25-hydroxyvitamin D status of vegetarians, partial vegetarians, and nonvegetarians: the Adventist Health Study-2 by Chan J, Jaceldo-Siegl K, Fraser GE in Am J Clin Nutr. 2009 May;89(5):1686S-1692S. "...We assessed serum 25-hydroxyvitamin D [s25(OH)D] concentrations and factors affecting them in vegetarians, partial vegetarians, and nonvegetarians in a sample of calibration study subjects...s25(OH)D concentrations were not associated with vegetarian status. Other factors, such as vitamin D supplementation, degree of skin pigmentation, and amount and intensity of sun exposure have greater influence on s25(OH)D than does diet."
  19. Should dairy be recommended as part of a healthy vegetarian diet? Counterpoint by Lanou AJ in Am J Clin Nutr. 2009 May;89(5):1638S-1642S. "...Although cow milk has been widely recommended in Western countries as necessary for growth and bone health, evidence collected during the past 20 y shows the need to rethink strategies for building and maintaining strong bones. Osteoporotic bone fracture rates are highest in countries that consume the most dairy, calcium, and animal protein. Most studies of fracture risk provide little or no evidence that milk or other dairy products benefit bone...Bones are better served by attending to calcium balance and focusing efforts on increasing fruit and vegetable intakes, limiting animal protein, exercising regularly, getting adequate sunshine or supplemental vitamin D, and getting approximately 500 mg Ca/d from plant sources. Therefore, dairy products should not be recommended in a healthy vegetarian diet."
  20. Vegetarian diets: what do we know of their effects on common chronic diseases? by Fraser GE in Am J Clin Nutr. 2009 May;89(5):1607S-1612S. "...The purpose of this review is to look critically at the evidence on the health effects of vegetarian diets and to seek possible explanations where results appear to conflict. There is convincing evidence that vegetarians have lower rates of coronary heart disease, largely explained by low LDL cholesterol, probable lower rates of hypertension and diabetes mellitus, and lower prevalence of obesity. Overall, their cancer rates appear to be moderately lower than others living in the same communities, and life expectancy appears to be greater....Although vegetarian diets are healthful and are associated with lower risk of several chronic diseases, different types of vegetarians may not experience the same effects on health."
  21. Should dairy be recommended as part of a healthy vegetarian diet? Point by Weaver CM in Am J Clin Nutr. 2009 May;89(5):1634S-1637S. "A benefit-risk evaluation of the evidence for including dairy foods in the diet is presented......Overall, evidence suggests that being a lactovegetarian has greater health benefits and reduced health risks than being a vegan."
  22. Do vegetarians have to eat fish for optimal cardiovascular protection? by Mangat I in Am J Clin Nutr. 2009 May;89(5):1597S-1601S. "Interest in the cardiovascular protective effects of n-3 (omega-3) fatty acids has continued to evolve during the past 35 y since the original research describing the low cardiovascular event rate in Greenland Inuit was published by Dyerberg et al...(T)here is insufficient evidence to recommend n-3 fatty acid supplementation for the purposes of cardiovascular protection..."
  23. Should dairy be recommended as part of a healthy vegetarian diet? Counterpoint by Lanou AJ in Am J Clin Nutr. 2009 May;89(5):1638S-1642S. "...Although cow milk has been widely recommended in Western countries as necessary for growth and bone health, evidence collected during the past 20 y shows the need to rethink strategies for building and maintaining strong bones. Osteoporotic bone fracture rates are highest in countries that consume the most dairy, calcium, and animal protein. Most studies of fracture risk provide little or no evidence that milk or other dairy products benefit bone...Bones are better served by attending to calcium balance and focusing efforts on increasing fruit and vegetable intakes, limiting animal protein, exercising regularly, getting adequate sunshine or supplemental vitamin D, and getting approximately 500 mg Ca/d from plant sources. Therefore, dairy products should not be recommended in a healthy vegetarian diet."
  24. Serum 25-hydroxyvitamin D status of vegetarians, partial vegetarians, and nonvegetarians: the Adventist Health Study-2 by Chan J, Jaceldo-Siegl K, Fraser GE in Am J Clin Nutr. 2009 May;89(5):1686S-1692S. "...We assessed serum 25-hydroxyvitamin D [s25(OH)D] concentrations and factors affecting them in vegetarians, partial vegetarians, and nonvegetarians in a sample of calibration study subjects...s25(OH)D concentrations were not associated with vegetarian status. Other factors, such as vitamin D supplementation, degree of skin pigmentation, and amount and intensity of sun exposure have greater influence on s25(OH)D than does diet."
  25. The relative impact of a vegetable-rich diet on key markers of health in a cohort of Australian adolescents by Grant R, Bilgin A, Zeuschner C, Guy T, Pearce R, Hokin B, Ashton J. in Asia Pac J Clin Nutr. 2008;17(1):107-15. "...We compared key physiological and biochemical markers of health against responses to a modified, Schools Physical Activity and Nutrition Survey (SPANS)...Adolescents consuming predominantly vegetarian foods showed significantly better scores on markers of cardiovascular health, including, body mass index (BMI), waist circumference, Cholesterol/High density lipoprotein ratio and low density lipoprotein. Adolescents consuming nuts more than once per week, also showed lower scores for BMI and serum glucose irrespective of their vegetarian status. Markers of general health including haemoglobin and average height were not different between groups; however a lower serum level of vitamin B12 was apparent in the vegetarian cohort. Surprisingly, exercise on its own was not statistically associated with any of the risk factors tested suggesting that diet may be the most significant factor in promoting health in this age group."
  26. Bone mineral density of vegetarian and non-vegetarian adults in Taiwan by Wang YF, Chiu JS, Chuang MH, Chiu JE, Lin CL in Asia Pac J Clin Nutr. 2008;17(1):101-6. "...In this study, we explored the potential impact of a vegetarian diet on bone mineral density (BMD) in adult Taiwanese men and women...(N)o statistical differences in BMD were observed between vegetarians and non-vegetarians of either sex. The proportion of subjects with osteopenia or osteoporosis also appeared comparable between vegetarians and non-vegetarians of either sex. BMD shows an age-related decline in Taiwanese men and women, and eating a vegetarian diet does not appear to affect this decline."
  27. Long-term strict raw food diet is associated with favourable plasma beta-carotene and low plasma lycopene concentrations in Germans by Garcia AL, Koebnick C, Dagnelie PC, Strassner C, Elmadfa I, Katz N, Leitzmann C, Hoffmann I in Br J Nutr. 2008 Jun;99(6):1293-300. "...(W)e investigated vitamin A and carotenoid status and related food sources in raw food diet adherents in Germany...Fat contained in fruits, vegetables and nuts and oil consumption was a significant dietary determinant of plasma carotenoid concentrations...Long-term raw food diet adherents showed normal vitamin A status and achieve favourable plasma beta-carotene concentrations as recommended for chronic disease prevention, but showed low plasma lycopene levels. Plasma carotenoids in raw food adherents are predicted mainly by fat intake."