Evidence-Based Nutrient Recommendations

Infrequent Animal Food Intake doesn’t Cure B12 Deficiency

There is evidence that B12 function cannot be restored to healthy levels by adding small amounts of animal products into the diet.

van Dusseldorp et al. (1999, Netherlands) investigated whether moderate consumption of animal products is sufficient for achieving normal B12 function in 73 adolescents who had been strict macrobiotics (MAC) until 6 years old and then switched to a lacto-ovo-vegetarian (LOV) or non-vegetarian (NV) diet. 94 people who had never been macrobiotic or vegetarian served as controls. Dairy supplied an average of ~1 µg B12/day for the MACs. They also ate fish, red meat, or chicken 2-3 times/week.

Table 1. van Dusseldorp et al.van Dusseldorp, 1999 (1999, Netherlands)
Number serum B12
sMMA Range
sMMA > .41 µmol/l HCY > 12.8 µmol/l
MAC Boys 37 288A .29 (.09-.93)C 24% 8%
Girls 36 389B .25 (.09-.70)D 17% 11%
Controls Boys 39 653A .15 (.06-.43)C 5% 5%
Girls 55 618B .17 (.07-.40)D
A,B,C,D – Statistically significant difference between groups with same letters

Thus, moderate animal product consumption was not enough to restore normal B12 status for 21% of these children, based on MMA levels.


van Dusseldorp M, Schneede J, Refsum H, Ueland PM, Thomas CM, de Boer E, van Staveren WA. Risk of persistent cobalamin deficiency in adolescents fed a macrobiotic diet in early life. J Clin Nutr. 1999 Apr;69(4):664-71.

Leave a comment

Your email address will not be published. Required fields are marked *

Before you comment, please read:

  • If you have a question about whether it's okay to cut supplements in half or combine supplements to achieve the dose we recommend, the answer is “Yes.” Be aware that nutrient recommendations are only estimates—it's not necessary to consume the exact amount we recommend every single day.
  • We aren't able to respond to questions about which brands of supplements to take.
  • We cannot provide personal nutrition advice for specific health conditions. If you need private counseling, here's a list of plant-based dietitians and we especially recommend VeganHealth contributor Taylor Wolfram, MS, RDN, LDN.
  • We urge you to consult with a qualified health professional for answers to your personal questions.