Pregnancy, Vitamin B12, and Folic Acid (B9)

B vitamins are essential co-factors for energy metabolism and neurological function. Vitamin B12 deficiency is common and can cause anemia and neurological disorders [1]. Fortified foods and supplements are an important dietary source of vitamin B12 [2]. Vitamin B12 deficiencies can be corrected by oral means or intramuscular injections; both are effective with oral forms being cheaper [1] and less invasive. Damayanti et al [2] report lower serum vitamin B12 and holotranscobalamin concentrations in adults consuming lesser amounts of vitamin B12 and in men versus women.

Under current food regulations, a food or supplement must provide 1.2 µg per serving (Reference Amount Customarily Consumed, RACC) to be an ‘excellent’ source of Vitamin B12. Regulations coming into effect January, 2020 will allow an ‘excellent’ source claim on products with only 0.48 µg/RACC [3]. This 60% reduction in vitamin B12 content per RACC has the potential to substantially decrease B12 intake from fortified foods and dietary supplements.

Women who are vegetarian are at increased risk of vitamin B12 deficiency. If they breast-feed their baby, the child is at risk for severe developmental abnormalities. It is important to encourage women who wish or may become pregnant to supplement with vitamin B12 and folic acid. The Daily Recommended Intake (DRI) for pregnant women is 2.6 µg vitamin B12 and 600 µg folic acid daily.


  1. Wang H, Li L, Qin LL, Song Y, Vidal‐Alaball J, Liu TH. Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. The Cochrane Library. John Wiley & Sons, Ltd; 2018. doi:10.1002/14651858.CD004655.pub3
  2. Damayanti D, Jaceldo-Siegl K, Beeson W, Fraser G, Oda K, Haddad E. Foods and Supplements Associated with Vitamin B12 Biomarkers among Vegetarian and Non-Vegetarian Participants of the Adventist Health Study-2 (AHS-2) Calibration Study. Nutrients. 2018;10: 722. doi:10.3390/nu10060722
  3. McBurney MI, Hartunian-Sowa S, Matusheski NV. Implications of US Nutrition Facts Label Changes on Micronutrient Density of Fortified Foods and Supplements. The Journal of Nutrition. 2017;147: 1025–1030. doi:10.3945/jn.117.247585

About Michael McBurney

Personal Blog | Nutrition scientist with broad interests, including social media and the impact of open access journals on science publishing | Self-employed freelancer
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1 Response to Pregnancy, Vitamin B12, and Folic Acid (B9)

  1. Ulrich Killeit says:

    Dear Michael,
    For sure you have seen this publication, which fits quite well to the topic above:
    Vitamin B-12 in Human Milk: A Systematic Review.
    Kind regards


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