B12 Status: Vegan Adults

Summary: VEgan adults who do not supplement with vitamin B12 tend have lower serum B12 levels than non-vegetarians. They sometimes have higher Mean Corpuscular Volume and MMA levels. They sometimes have overt B12 deficiency symptoms. These charactiristics increase the longer one is on a vegan diet. Vegans who supplement their diets with vitamin B12 tend to have serum B12 levels in the normal range, but could stand to increase them to 350 - 405 pg/ml to ensure healthy homocysteine levels and reduce DNA damage.

Individual cases of overt B12 deficiency are listed in B12 Status: Individual Cases. Additional studies of vegan B12 status are located in Homocysteine, B12, Vegetarians, and Disease.

Studies on Adult Vegans Not Supplementing with B12

Australians have a lifestyle similar to North Americans, but with limited B12 fortified foods. Hokin & Butler (1999) examined Australian Seventht-day Adventist ministers, aged 22-80, who did not take B12 supplements. The results in the table below showed vegans to have significantly lower B12 levels.

Results of Hokin & Butler
	#	B12 (range)	Malabsorption / IF deficiency
NV	53	394^A ± 196 (181-973)	NR
LOV	234	NR^B	20% / 10%
Vegans	11	224^A ± 100 (99-420)	NR
Total	298
A – Statistically significant difference between groups with same letters B - Not significantly different from the NV NR - Not reported NV – Non-vegetarians

Reference: Hokin BD, Butler T. Cyanocobalamin (vitamin B-12) status in Seventh-day Adventist ministers in Australia. Am J Clin Nutr. 1999 Sep;70(3 Suppl):576S-578S.

Crane et al. (1998, USA) studied 2 families (9 people) who were vegan for over 1 year and who did not regularly take B12 supplements or fortified foods:

They ate food from their gardens or local grocery stores.
Serum B12 (sB12) was below 200 pg/ml in 8 members; average sB12 was 190 ± 65 pg/ml.
The only family member over 200 pg/ml, with a B12 level of 331 pg/ml, was also the only one with signs of deficiency (mild numbness in one hand and easy fatigue). These cleared up after starting oral B12, so her high levels might be attributable to inactive B12 analogues.
8 had high urinary MMA.
Homocysteine levels were in the normal range, but dropped after B12 therapy.
The subjects were given 500 µg B12/day, which they chewed before swallowing. After 2 months:

Average red blood cell count increased.
Average total cholesterol decreased by 10.3% and LDL cholesterol decreased by 19.6%. (Note: This is the only study that observed a cholesterol reduction in vegans because of B12 supplementation.)
Serum MMA levels dropped dramatically (from .65 ± .61 to .13 ± .06 µmol/l).
Average sB12 rose to 553 ± 113 pg/ml.

Crane et al. write:

The laboratory evidence in these two families is too strong to believe that they had an adequate amount of [B12]. It is remarkable that they had been on a total vegetarian diet for so long, yet with little or no clinical symptoms or signs of an insufficiency of cobalamin. In this study none of the family members were aware of symptoms of easy fatigability, tingling in the extremities, or frequent upper respiratory infections.

Reference: Crane MG, Register UD, Lukens RH, Gregory R. Cobalamin (CBL) studies on two total vegetarian (vegan) families. Vegetarian Nutrition. 1998; 2(3):87-92.

Crane et al. (1994, USA) measured the sB12 of healthy adult vegans (1-28 years on the diet) who had not used B12 supplements or fortified foods in the previous year or more. Results were:

Results of Crane et al.
	#	sB12 < 200 pg/ml	sB12 < 100 pg/ml	sB12 range
no FF or SUP for 1 yr	76	47 (62%)	19%	41-615
fortified soymilk for 1 yr	20^A			304-540
A - 8 were children FF - Fortified foods sB12 - Serum B12 SUP - supplements

Participants with low B12 levels were given oral B12. The B12 levels of some of these participants did not increase, which led to the study about chewing B12 tablets mentioned under Chew or Dissolve Supplements Under the Tongue in Sources of B12 for Vegans.

Crane et al. also examined urinary MMA levels in 29 vegan adults who had not used B12 supplements or fortified foods in the previous year:

11 had B12 levels < 200 pg/ml. Their average MCV (95.9 ± 5.5 fl) was significantly higher than those with higher B12 levels.
7 of these 11 had high MMA.
None with normal B12 levels had elevated MMA.
One vegan of 5 years had no symptoms of B12 deficiency despite a sB12 of 90 pg/ml. However, after 1 month of oral B12, he noticed that his chronic indigestion after meals had disappeared.

Reference: Crane MG, Sample C, Pathcett S, Register UD. "Vitamin B12 studies in total vegetarians (vegans). Journal of Nutritional Medicine. 1994;4:419-430.

Tungtrongchitr et al. (1993, Thailand) studied 132 Thai adult vegetarians (64 males, 68 females) and 47 healthy nonvegetarians. The vegetarians apparently ate no animal products. Serum B12 levels were:

Results of Tungtrongchitr et al.
	Serum B12	Serum B12 range
Male NV	490	176-825
Female NV	500	270-1400
Male Veg	117	31-730
Female Veg	153	22-460
NV – Non-vegetarians

There were some blood cell differences between vegetarians and non-vegetarians. Serum B12 decreased as years as a vegetarian increased. Groups practicing vegetarianism for ≥ 6 years resulted in particularly low average sB12 levels (83-135 pg/ml).

Reference: Tungtrongchitr R, Pongpaew P, Prayurahong B, Changbumrung S, Vudhivai N, Migasena P, Schelp FP. Vitamin B12, folic acid and haematological status of 132 Thai vegetarians. Int J Vitam Nutr Res. 1993;63(3):201-7.

Bar-Sella et al. (1990, Israel) compared 36 vegans (5-35 years on diet) to 36 non-vegetarians. None of the vegans used supplements. Vegans had significantly lower levels of B12 (164 vs. 400 pg/ml). No non-vegetarian was deficient in B12, but 2 were borderline. No subjects had blood abnormalities. 4 vegans had a history of muscle pain, abnormal sensations in the legs, and difficulty concentrating. Their serum B12 levels were:

B12 Levels in 4 Vegans with History of Nerve-related Problems
Subject	1	2	3	4
Age	56	64	40	57
Serum B12 (pg/ml)	65	84	89	90

3 of the 4 were followed and showed substantial clinical improvement after B12 injections which increased their B12 levels to over 200 pg/ml.

Reference: Bar-Sella P, Rakover Y, Ratner D. Vitamin B12 and folate levels in long-term vegans. Isr J Med Sci. 1990;26:309-312.

Areekul et al. (1988, Thailand) found a significant difference between B12 levels (62 ± 78 pg/ml) in 29 apparently healthy vegetarians and 60 omnivores (629 ±160 pg/ml). 8 vegetarians had undetectable B12 levels, while only 2 had levels over 200 pg/ml. The researchers did not state whether any of the vegetarians were taking B12 supplements, but they appeared not to be doing so.

Reference: Areekul S, Churdchu K, Pungpapong V. Serum folate, vitamin B12 and vitamin B12 binding protein in vegetarians. J Med Assoc Thai. 1988 May;71(5):253-7.

Vegans Taking B12 Supplements

Haddad et al. (1999, USA) compared vegans to non-vegetarians. Results were:

Results of Haddad et al.
	#	yrs on diet	# taking B12 SUP^A,B	B12 (pg/ml)	# with B12 < 203	sMMA > .38 µmol/l	Had 1 Indicator of B12 deficiency
Vegans	25	4.2 (1-25)	9	421 ± 169	3	5	10
NV	20			423 ± 134	0	0
A - Per correspondence with author B - Some vegans ate B12 fortified foods SUP - Supplements

There were no differences in homocysteine between the groups. There was a significant association between B12 supplementation and sB12 but no relation with sMMA. In private correspondence, Haddad suggested this was because some vegans did not regularly take the supplements and some had only recently begun. Blood will reflect recent higher B12 intake while MMA levels take longer to change.

Reference: Haddad EH, Berk LS, Kettering JD, Hubbard RW, Peters WR. Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians. Am J Clin Nutr. 1999;70(suppl):586S-93S.

Harman & Parnell (1998, New Zealand) compared 24 adult vegetarian Seventh-day Adventists (SDA) (including some vegans; number not specified) to 23 non-vegetarian SDAs. Some vegetarians were taking B12 supplements and injections. Results were:

Results of Harman & Parnell
	sB12 (pg/ml)
Male Vegetarians	220 ± 103
Female Vegetarians	282 ± 132
Male NV	331 ± 142
Female NV	331 ± 167
NV – Non-vegetarian

B12 levels did not differ significantly between groups.

Reference: Harman SK, Parnell WR. The nutritional health of New Zealand vegetarian and non-vegetarian Seventh-day Adventists: selected vitamin, mineral and lipid levels. NZ Med J. 1998 Mar 27;111(1062):91-4.

Alexander et al. (1994, New Zealand) looked at 18 vegetarians. B12 levels were:

B12 levels in Alexander et al.
	#	Years on diet	sB12
Vegan	5	6.6 (1-12)	277
LOV	13	> 5	229

Other findings were as follows:

6 had B12 levels below the reference range: 82, 86, 182, 190, 197 (vegan or LOV wasn't specified). None had macrocytosis. The woman with the lowest value was found to have an intrinsic factor deficiency.
7 vegetarians took B12 supplements and only one had low B12 levels, but their levels were not significantly different than those who did not take supplements.
The vegans actually had a higher average sB12 than the LOV.

Reference: Alexander D, Ball MJ, Mann J. Nutrient intake and haematological status of vegetarians and age-sex matched omnivores. European Journal of Clinical Nutrition. 1994;48:538-546.

Sanders et al. (1978, UK) compared adult vegan (no animal products ≥ 1 year; average 8 yrs) members of The Vegan Society (UK) to age and sex matched non-vegetarians. 18 of the vegans were taking B12 supplements or eating fortified foods. Results were:

Sanders et al. (1978, UK)
	Serum B12 (pg/ml)
22 Vegans	289 R 120-675
22 NV	371 R 250-775
NV - Non-vegetarian

5 vegans were not taking B12 supplements or fortified foods:

Sanders et al. (1978, UK)
Years as vegan	2	4	6	6	13
Serum B12	200	225	230	180	120

The results indicate that supplementing vegans had higher sB12 levels than non-supplementing.

Reference: Sanders TA, Ellis FR, Dickerson JW. Studies of vegans: the fatty acid composition of plasma choline phosphoglycerides, erythrocytes, adipose tissue, and breast milk, and some indicators of susceptibility to ischemic heart disease in vegans and omnivore controls. Am J Clin Nutr. 1978 May;31(5):805-13.