Skip to main content Accessibility help

Effects of a 3-month dietary intervention with a lacto-ovo-vegetarian diet on vitamin B12 levels in a group of omnivores: results from the CARDIVEG (Cardiovascular Prevention with Vegetarian Diet) study

  • M. Dinu (a1), G. Pagliai (a1), F. Cesari (a2), B. Giusti (a1) (a3), A. M. Gori (a1) (a3), R. Marcucci (a1) (a3), A. Casini (a1) (a4) and F. Sofi (a1) (a4) (a5)...


Previous studies have suggested that vegetarianism can result in a reduction of vitamin B12 circulating levels. The aim of the present study was to investigate the effects of a 3-month dietary intervention with a lacto-ovo-vegetarian diet (VD) on the levels of circulating vitamin B12 in a group of omnivores. We analysed fifty-four omnivorous subjects who followed a VD as a first dietary intervention within the CARDIVEG (Cardiovascular Prevention with Vegetarian Diet) study, a dietary intervention study. VD resulted in a significant reduction (P<0·001) of 51·2 % of vitamin B12 intake and in a significant reduction (P=0·005) of 6·2 % of the circulating levels of vitamin B12 (–24·5 pg/ml). Changes in vitamin B12 intake were significantly correlated with changes in circulating levels of vitamin B12 (R 0·61, P<0·001). Subgroup analyses showed that reduction in circulating vitamin B12 levels was more evident in participants who were younger, overweight, non-smokers and had hypercholesterolaemia. A logistic regression analysis showed that a reduction in vitamin B12 intake greater than the first quartile of the delta changes obtained in the study population (–28·5 %) conferred a significantly higher risk of experiencing a decrease in circulating vitamin B12 levels (OR 10·1; 95 % CI 1·3, 76·1). In conclusion, a 3-month VD period determined a significant reduction in circulating levels of vitamin B12, being significantly correlated with the reduction in vitamin B12 intake. Although a well-planned VD can provide adequate nutrition across all life stages, special care must be taken to ensure adequate vitamin B12 intake and to help prevent deficiency.


Corresponding author

*Corresponding author: M. Dinu, email


Hide All
1. Leitzmann, C (2016) Vegetarian nutrition: past, present, future. Am J Clin Nutr 100, 496S502S.
2. Melina, V, Craig, W & Levin, S (2016) Position of the Academy of Nutrition and Dietetics: vegetarian diets. J Acad Nutr Diet 116, 19701980.
3. Wheatley, C (2007) The return of the Scarlet Pimpernel: cobalamin in inflammation II—cobalamins can both selectively promote all three nitric oxide synthases (NOS), particularly iNOS and eNOS, and, as needed, selectively inhibit iNOS and nNOS. J Nutr Environ Med 16, 181211.
4. Homocysteine Studies Collaboration (2002) Homocysteine and risk of ischemic heart disease and stroke: a meta-analysis. JAMA 288, 20152022.
5. Gilsing, AM, Crowe, FL, Lloyd-Wright, Z, et al. (2010) Serum concentrations of vitamin B12 and folate in British male omnivores, vegetarians and vegans: results from a cross-sectional analysis of the EPIC-Oxford cohort study. Eur J Clin Nutr 64, 933939.
6. Pawlak, R, Lester, SE & Babatunde, T (2014) The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature. Eur J Clin Nutr 68, 541548.
7. Madry, E, Lisowska, A, Grebowiec, P, et al. (2012) The impact of vegan diet on B-12 status in healthy omnivores: five-year prospective study. Acta Sci Pol Technol Aliment 11, 209212.
8. Rizzo, G, Laganà, AS, Rapisarda, AM, et al. (2016) Vitamin B12 among vegetarians: status, assessment and supplementation. Nutrients 8, E767.
9. Kestin, M, Rouse, IL, Correll, RA, et al. (1989) Cardiovascular disease risk factors in free-living men: comparison of two prudent diets, one based on lacto-ovo-vegetarianism and the other allowing lean meat. Am J Clin Nutr 50, 280287.
10. Prescott, SL, Jenner, DA, Beilin, LJ, et al. (1988) A randomized controlled trial of the effect on blood pressure of dietary nonmeat protein versus meat protein in normotensive omnivores. Clin Sci (Lond) 74, 665672.
11. Sciarrone, SE, Strahan, MT, Beilin, LJ, et al. (1993) Biochemical and neurohormonal responses to the introduction of a lactoovovegetarian diet. J Hypertens 11, 849860.
12. Burke, LE, Hudson, AG, Warziski, MT, et al. (2007) Effects of a vegetarian diet and treatment preference on biochemical and dietary variables in overweight and obese adults: a randomized clinical trial. Am J Clin Nutr 86, 588596.
13. Gardner, CD, Coulston, A, Chatterjee, L, et al. (2005) The effect of a plant-based diet on plasma lipids in hypercholesterolemic adults – a randomized trial. Ann Intern Med 142, 725733.
14. Sofi, F, Dinu, M, Pagliai, G, et al. (2016) Mediterranean versus vegetarian diet for cardiovascular disease prevention (the CARDIVEG study): study protocol for a randomized controlled trial. Trials 17, 233.
15. Sofi, F, Dinu, M, Pagliai, G, et al. (2018) Low-calorie vegetarian versus Mediterranean diets for reducing body weight and improving cardiovascular risk profile: CARDIVEG Study (Cardiovascular Prevention with Vegetarian Diet). Circulation 137, 11031113.
16. Centers for Disease Control and Prevention. NHANES food questionnaire. (accessed October 2018).
17. Obersby, D, Chappell, DC, Dunnett, A, et al. (2013) Plasma total homocysteine status of vegetarians compared with omnivores: a systematic review and meta-analysis. Br J Nutr 109, 785794.
18. USDA food composition database; USDA national nutrient database for standard reference. (accessed October 2018).
19. Banca Dati Di Composizione Degli Alimenti per Gli Studi Epidemiologici in Italia (BDA) (Food Composition Database for Epidemiological Studies in Italy (BDA)). (accessed October 2018).
20. Watanabe, F (2007) Vitamin B12 sources and bioavailability. Exp Biol Med 232, 12661274.
21. Partearroyo, T, Samaniego-Vaesken, ML, Ruiz, E, et al. (2017) Dietary sources and intakes of folates and vitamin B12 in the Spanish population: findings from the ANIBES study. PLOS ONE 12, e0189230.
22. Sukumar, N, Adaikalakoteswari, A, Venkataraman, H, et al. (2016) Vitamin B12 status in women of childbearing age in the UK and its relationship with national nutrient intake guidelines: results from two National Diet and Nutrition Surveys. BMJ Open 6, e011247.
23. Hunt, A, Harrington, D & Robinson, S (2014) Vitamin B12 deficiency. BMJ 349, g5226.
24. Margalit, I, Cohen, E, Goldberg, E, et al. (2018) Vitamin B12 deficiency and the role of gender: a cross-sectional study of a large cohort. Ann Nutr Metab 72, 265271.
25. Tanaka, T, Scheet, P, Giusti, B, et al. (2009) Genomewide association study of vitamin B6, vitamin B12, folate, and homocysteine blood concentrations. Am J Hum Genet 84, 477482.
26. Wiebe, N, Field, CJ & Tonelli, M (2018) A systematic review of the vitamin B12, folate and homocysteine triad across body mass index. Obes Rev 19, 16081618.
27. Adaikalakoteswari, A, Jayashri, R, Sukumar, N, et al. (2014) Vitamin B12 deficiency is associated with adverse lipid profile in Europeans and Indians with type 2 diabetes. Cardiovasc Diabetol 13, 129.
28. Adaikalakoteswari, A, Finer, S, Voyias, PD, et al. (2015) Vitamin B12 insufficiency induces cholesterol biosynthesis by limiting s-adenosylmethionine and modulating the methylation of SREBF1 and LDLR genes. Clin Epigenetics 7, 14.
29. Dastur, DK, Quadros, EV, Wadia, NH, et al. (1972) Effect of vegetarianism and smoking on vitamin B12, thiocyanate, and folate levels in the blood of normal subjects. Br Med J 3, 260263.
30. Del Bo’, C, Riso, P, Gardana, C, et al. (2018) Effect of two different sublingual dosages of vitamin B12 on cobalamin nutritional status in vegans and vegetarians with a marginal deficiency: a randomized controlled trial. Clin Nutr (epublication ahead of print version 15 February 2018).
31. Sobiecki, JG, Appleby, PN, Bradbury, KE, et al. (2016) High compliance with dietary recommendations in a cohort of meat eaters, fish eaters, vegetarians, and vegans: results from the European Prospective Investigation into Cancer and Nutrition-Oxford study. Nutr Res 36, 464477.
32. Hokin, BD & Butler, T (1999) Cyanocobalamin (vitamin B-12) status in Seventh-day Adventist ministers in Australia. Am J Clin Nutr 70, 576S578S.
33. Pawlak, R (2015) Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians? Am J Prev Med 48, e11e26.
34. Appleby, PN, Crowe, FL, Bradbury, KE, et al. (2016) Mortality in vegetarians and comparable nonvegetarians in the United Kingdom. Am J Clin Nutr 103, 218230.
35. Chang-Claude, J, Hermann, S, Eilber, U, et al. (2005) Lifestyle determinants and mortality in German vegetarians and health-conscious persons: results of a 21-year follow-up. Cancer Epidemiol Biomarkers Prev 14, 963968.


Effects of a 3-month dietary intervention with a lacto-ovo-vegetarian diet on vitamin B12 levels in a group of omnivores: results from the CARDIVEG (Cardiovascular Prevention with Vegetarian Diet) study

  • M. Dinu (a1), G. Pagliai (a1), F. Cesari (a2), B. Giusti (a1) (a3), A. M. Gori (a1) (a3), R. Marcucci (a1) (a3), A. Casini (a1) (a4) and F. Sofi (a1) (a4) (a5)...


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed