Cyanocobalamin

Studies in people

• Benefit

  Low vitamin levels²

  Vitamin B12 is needed for DNA and energy, and low levels are common in vegetarians and older people.

• Benefit

  Oral treatment works⁴

  In 26 people with pernicious anemia, oral cyanocobalamin corrected vitamin B12 deficiency in 88.5% within one month.

• Open question

  Vitamin shots causing acne⁵

  In healthy people given vitamin B12 shots, one of ten developed acne a week later.

• Open question

  B12 supplement need⁷

  Vegetarians may need cyanocobalamin supplements since plant foods rarely provide enough vitamin B12.

• Open question

  B12 deficiency risk⁸

  Vegan adults had lower vitamin B12 status than meat eaters, but vegans who took vitamin B12 supplements had better levels.

• Open question

  Autism risk in children⁹

  Vitamin B12 may be one risk factor for autism, but studies so far disagree, so more research is needed.

• Benefit

  Teenage bone strength¹⁰

  In teens aged 12 to 19, eating more vitamin B12 was linked to stronger bones, but more studies are needed.

• Benefit

  B12 deficiency markers¹²

  In older people, a doubling of vitamin B12 intake was linked to higher total B12 and HoloTC and lower MMA and tHcy.

• Open question

  B vitamin deficiency trends¹³

  Vitamin B12 deficiency stayed common in Brazilian adults, though taking B-complex supplements was linked to higher levels.

How it’s made and used

• Nutrient absorption at meals³

  How much cyanocobalamin the body absorbs drops when you eat more of it in one meal.

• Low B12 from diet⁶

  Low intake of animal foods can cause low vitamin B12, and strict vegetarians are at risk.

• Blood pressure and B12 levels¹¹

  In 1,398 rural Punjabi adults, low vitamin B12 was common and went with higher homocysteine, which was linked to high blood pressure.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.