Vitamin B12 is a member of the all important vitamin B family.  Vitamin B12  is water soluble and vital for many physiologic processes such as proper nerve function, energy production, and DNA synthesis & repair.

Vitamin B12 is naturally found in animal derived foods, added to whole grains, and also available as a dietary supplement. Eventhough vitamin B12 is water-soluble, our body is able to store vitamin B12 for up to 4 years.

As we age are ability to absorb vitamin B12 diminishes, putting as at greater risk for deficiency. Additionally, strict vegetarians are at greater risk for deficiency given the absence of animal products in their diet.

Musculoskeletal Benefits of Vitamin B12

Vitamin B12 is required for the conversion of homocysteine to methionine. High levels of homocysteine have been associated with:

  • Oxidative stress
  • Chronic inflammation
  • Increased fracture risk
  • Decreased bone mineral density
  • Collagen dysfunction

Oxidative stress, chronic inflammation, and collagen dysfunction are associated with chronic musculoskeletal diseases such as osteoporosis, sarcopenia(muscle loss and weakness), osteoarthritis, and tendonitis. 

Vitamin B12 helps convert harmful levels of homocysteine to healthful levels of methionine, an essential amino acid. Also, methionine is required fro S-adenosylmethionine (SAM) a universal methyl donor that is involved in the synthesis of over 100 substances including DNA, RNA, hormones, proteins, and good fats.

Muscle and bone are metabolically hyper active; constantly building and breaking down. Any disruption in the building process causes a shift to an overall state of breakdown or “catabolism”. Many musculoskeletal diseases such as osteoporosis, osteoarthritis, and sarcopenia can be conceptualized as a situation in which the cellular machinery that destroys overwhelms the cellular machinery that builds. Insufficient vitamin B12 can magnify and accelerate this catabolic process.

Moreover, vitamin B12 helps the body metabolize fats and protein to use for fuel. Thus, vitamin B12 helps ensure bone cells, muscle cells, and joint cells have enough energy to maintain cellular health, repair, and grow.

Selected Evidence

1. Vitamin B12 Boosts Bone Health

Turkish researchers examined the relationship of homocysteine and B12 with osteoporosis.The investigators found that high homocysteine serum and low vitamin B12 levels were associated with osteoporosis. (Bozkurt et al. The relationship of homocysteine, B12 and folic acid with the bone mineral density of the femur and lumbar spine in Turkish postmenopausal women.Arch Gynecol Obstet. 2009 Sep;280(3):381-7.)

2. Vitamin B12 Supports Muscle Health

Researchers in the Netherlands examined the nutritional status of older adults with and without sarcopenia.The investigators found that the serum concentration of vitamin B12 was 15% lower in the sarcopenic group compared to the non-sarcopenic group. (Verlaan et al. Nutritional status, body composition, and quality of life in community-dwelling sarcopenic and non-sarcopenic older adults: A case-control study.Clin Nutr. 2017 Feb;36(1):267-274.)

Homocysteine Metabolism

Other Health Benefits 

There are other conditions that vitamin B12 may assist, although more research is needed and for some conditions results to date have been mixed. Those include:

  • Supports proper formation of red blood cells
  • Promotes neurological health
  • Enhances heart health
  • Aids in digestion

Natural sources of vitamin B12

Animal-based foods are the best sources of vitamin B12, including cage-free eggs, organic grass-fed dairy products, grass-fed meat, organic poultry, organ meats, and wild-caught fish. Plant foods, unless synthetically fortified, do not naturally contain vitamin B12.


Recommended Dietary Allowance (RDA)

The Food and Nutrition Board has developed a table of recommended dietary allowances (RDAs) of vitamin B12, based on age and gender. The values are:

  • Infants aged up to 6 months: 0.4 micrograms (mcg)
  • Babies aged 7 to 12 months: 0.5 mcg
  • Children aged 1 to 3 years: 0.9 mcg
  • Kids aged 4 to 8 years: 1.2 mcg
  • Children aged 9 to 13 years: 1.8 mcg
  • Teens aged 14 to 18: 2.4 mcg (2.6 mcg per day if pregnant and 2.8 mcg per day if breastfeeding)
  • Adults: 2.4 mcg (2.6 mcg per day if pregnant and 2.8 mcg per day if breastfeeding)


Vitamin B12 from natural foods is generally well tolerated. RDA amounts can usually be obtained from a balanced, healthful diet.

Upper limits for vitamin B12 consumption have not been established given vitamin B12's low potential for toxicity.

However, any consideration of supplementation should be discussed with a qualified health professional familiar with your unique medical history. 



University of Florida Institute of Food and Agricultural Sciences (IFAS) Extension: "Facts About Vitamin B12."

University of Arizona’s Arizona Telemedicine Program: "Vitamin B12 Deficiency: Pernicious Anemia."

Harvard Health Publications: "Vitamin B12 Deficiency: Vegetarians, elderly may not get enough vitamin B12, says the Harvard Health Letter."

National Heart, Lung, and Blood Institute: "Pernicious Anemia."

Oregon State University’s Linus Pauling Institute: "Vitamin B12."

Kaiser Permanente: "Vitamin B12 Deficiency Anemia."

National Institutes of Health Office of Dietary Supplements: "Vitamin B12."

MedlinePlus: "Anemia -- B12 deficiency."

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