What is Vitamin B12?

Vitamin B12 is one of the most important B vitamins. It works with folate in many body processes. Vitamin B12 works to reactivate folate, so if B12 is deficient then it is likely that folate will also be deficient. It occurs in two main forms – hydroxocobalamin and cyanocobalamin. Cyanocobalamin is converted in the body to methylcobalamin or adenosylcobalamin by the removal of the cyanide molecule. Methylcobalamin is the most active form.

Vitamin B12 primarily occurs in seafood and animal products. Since this is so, deficiencies in the diet of vegans and strict vegetarians may cause them to develop pernicious anemia. Vitamin B12 (unlike other B vitamins) is stored in the liver, kidneys, and other body tissues, and therefore deficiency symptoms may not appear for months, or years, until its reservoirs in the body are depleted.

Why is Vitamin B12 important and what does it do in the body?

Vitamin B12 is important in many biological processes:

  • It is essential for the body’s healthy metabolism and the function of all cells.
  • It helps form red blood cells in the bone marrow and promotes growth and appetite in children.
  • It is vital for the maintenance of a healthy nervous system and for brain function including memory, learning ability, and balance.
  • It assists in the function of iron, vitamin C, vitamin B5, folate, and choline.
  • It can also support regular menstruation and prevents postnatal depression.
  • It is used in supporting the synthesis of DNA and the myelin sheath surrounding each nerve cell and fiber.

Both vitamin B12 and folate are what are known as “methyl donors” which support the body in many positive ways especially in reducing homocysteine, increasing energy metabolism and immune and nerve function.


What amount of Vitamin B12 do you need each day?

The DRI (Daily Recommended Intake) /RDA (Recommended Daily Allowance) of dietary vitamin B12 is 2mcg/Day for adult, nonsmoking men and women.

What foods contain the highest amounts of Vitamin B12?

The TOP 10 Vitamin B12 rich foods are:
  1. Cooked clams 98.9mcg/100g
  2. Liver 83.1mcg/100g
  3. Rice bran 20mcg/100g
  4. Mackerel 19mcg/100g
  5. Herring 10mcg/100g
  6. Sardines 8 mcg/100g
  7. Egg yolk 2.0mcg/100g
  8. Beef 6.0mcg/100g
  9. Lamb 5.2mcg/100g
  10. Eggs 2.0mcg/100g

I try and include as many of these foods as possible into my daily diet! Some recipe ideas to try include:

Huevos Rancheros

Hibachi Beef Bowl

Shepherd’s Pie

References:

Balch, J. F., & Balch, P. A. (1990). Prescription for nutritional healing. Garden City Park, NY: Avery Publishing Group.

Gibson, R. S. (2005). Principles of nutritional assessment. Oxford: Oxford University Press.

Holford, P. (1999). Optimum Nutrition Bible. Crossing.

Hunt, S. M., & Groff, J. L. (n.d.). Advanced nutrition and human metabolism. St. Paul: West Publ. Co.

Lord, R. S., & Bralley, J. A. (2012). Laboratory evaluations for integrative and functional medicine. Duluth, Ga: Genova Diagnostics.

Liska, D. A., & Bland, J. (2004). Clinical nutrition: a functional approach. Gig Harbor, WA: Institute for Functional Medicine.

Murray, M. T. (2002). The encyclopedia of nutritional supplements. Rocklin, CA: Prima.

MARTIN, D. W. J. R., MAYES, P. A., & RODWELL, V. W. (1981). Harpers Review Of Biochemistry. Los Altos, CA, LANGE MEDICAL PUBLICATIONS.

Sharon, M. (2001). Complete Nutrition. Prion Books; London.