B12, Folic Acid, & MTHFR

How does a vitamin deficiency contribute to pernicious anemia or a confused state?

Pernicious anemia is an autoimmune disease that impairs dietary cobalamin absorption resulting in a deficiency of B12. This impaired absorption is due to the autoimmune destruction of the gastric parietal cells that produce intrinsic factor (Green & Datta Mitra, 2017). Vitamin B12 is vital for blood cell development and nerve myelination (Mohamed et al., 2020). Deficiency of vitamin B12 can cause neurological damage due to impaired development of succinyl coenzyme A which is essential for forming myelin sheaths (Lenti et al., 2020). Neuronal demyelination and associated degeneration result in neurological and neuropsychiatric symptoms (Mohamed et al., 2020).

(Mohamed et al., 2020)

What other vitamins and nutrients should a patient on diuretics include in the diet?

Diuretics can contribute to magnesium, calcium, thiamine, potassium, zinc, and folic acid deficiency. These would need to be evaluated and supplemented if necessary (Natural Medicines, n.d.). A synergistic relationship exists between vitamin B12 and folate, and folic acid deficiency often coexists with B12 deficiency (Gropper, Smith, & Carr, 2018).

Hypertension Treatment (Rakel, 2018)


  • Follow the DASH diet eating plan with its emphasis on foods rich in potassium, magnesium, calcium, and nitrates
  • Reduce dietary sodium to less than 2.4 grams per day (1 tsp)
  • Limit alcohol to two drinks or less per day for men and one drink or less per day for women
  • Consider 10 to 30 grams per day of 70% cacao dark chocolate
  • Consider 30 grams per day of flax seed
  • Consider 30 grams per day of dietary fiber


  • Maintain a serum 25-OH-vitamin D greater than 40 ng/mL
  • Ensure 1000 mg a day of EPA and DHA by fish or krill oil
  • Consider CoQ10 to achieve a serum level > 2.0 μg/mL
  • Consider absorbable magnesium at 6 mg/kg.

Sources of folate that a patients should avoid if they have a MTHFR diagnosis.

Although a patient with MTHFR gene mutations will have a more difficult time metabolizing folic acid, it does not mean that it is not safe. A better choice would be to take 5-methyltetrahydrofolate (5-MTHF), but it has not been shown to reduce the risk of neural tube defects. Natural food folates can be found in vegetables (especially dark green leafy vegetables), fruits, nuts, beans, peas, seafood, eggs, dairy products, meat, poultry, and grains (CDC, n.d.).


CDC. (n.d.). MTHFR Gene, Folic Acid, and Preventing Neural Tube Defects. Retrieved September 12, 2020, from https://www.cdc.gov/ncbddd/folicacid/mthfr-gene-and-folic-acid.html

Green, R., & Datta Mitra, A. (2017). Megaloblastic Anemias: Nutritional and Other Causes. Medical Clinics of North America, 101(2), 297–317. https://doi.org/10.1016/j.mcna.2016.09.013

Gropper, S. S., Smith, J. L., & Carr, T. P. (2018). Advanced Nutrition and Human Metabolism (7th ed.). Cengage Learning. https://doi.org/10.1111/j.1753-4887.1997.tb01621.x

Lenti, M. V., Rugge, M., Lahner, E., Miceli, E., Toh, B. H., Genta, R. M., De Block, C., Hershko, C., & Di Sabatino, A. (2020). Autoimmune gastritis. Nature Reviews Disease Primers, 6(1). https://doi.org/10.1038/s41572-020-0187-8

Mohamed, M., Thio, J., Thomas, R. S., & Phillips, J. (2020). Pernicious anaemia. The BMJ, 369, 10–14. https://doi.org/10.1136/bmj.m1319

Rakel, D. (2018). Integrative Medicine (Fourth). Elsevier.

Natural Medicines. (n.d.). Drug-Induced Depletions. Retrieved September 12, 2020, from https://naturalmedicines.therapeuticresearch.com/tools/charts/drug-induced-nutrient-depletions.aspx

*These statements are not meant to diagnose or treat. You should consult your health care provider before starting any new diet, exercise, or supplement.