Both cyanocobalamin and methylcobalamin are forms of vitamin B12. Cyanocobalamin is synthetic while methylcobalamin is natural. But the body can convert synthetic forms into natural ones.
Vitamin B12also known as cobalaminis an important water-soluble vitamin involved in red blood cell productionbrain healthand DNA synthesis (1).
A deficiency in this key vitamin can cause serious symptomsincluding fatiguenerve damagedigestive issuesand neurological problems like depression and memory loss (1).
Thereforemany people turn to vitamin B12 supplements to help meet their needs and prevent a deficiency.
This article examines the main differences between methylcobalamin and cyanocobalamin — two of the most common sources of vitamin B12 found in supplements.
Vitamin B12 supplements are typically derived from two sources: cyanocobalamin or methylcobalamin.
Both are nearly identical and contain a cobalt ion surrounded by a corrin ring.
Howevereach have a different molecule attached to the cobalt ion. While methylcobalamin contains a methyl groupcyanocobalamin contains a cyanide molecule.
Cyanocobalamin is a synthetic form of vitamin B12 that’s not found in nature (2).
It’s used more frequently in supplementsas it’s considered more stable and cost effective than other forms of vitamin B12.
When cyanocobalamin enters your bodyit’s converted into either methylcobalamin or adenosylcobalaminwhich are the two active forms of vitamin B12 in humans (1).
Unlike cyanocobalaminmethylcobalamin is a naturally occurring form of vitamin B12 that can be obtained through supplementsas well as food sources like fishmeateggsand milk (34).
SUMMARY
Cyanocobalamin is a synthetic form of vitamin B12 found only in supplementswhile methylcobalamin is a naturally occurring form that you can get through either food sources or supplements.
Another major difference between methylcobalamin and cyanocobalamin is the way they’re absorbed and retained within your body.
Some studies suggest that your body may absorb cyanocobalamin slightly better than methylcobalamin.
In factone study found that people’s bodies absorbed about 49% of a 1-mcg dose of cyanocobalamincompared to 44% of the same dose of methylcobalamin (5).
Converselyanother study comparing the two forms reported that about three times as much cyanocobalamin was excreted through urineindicating that methylcobalamin may be retained better within your body (6).
Howeversome research suggests that differences in bioavailability between the two forms may be insignificant and that absorption could be influenced by factors such as age and genetics (78).
Unfortunatelyrecent research directly comparing these two forms of vitamin B12 is limited.
Additional studies are needed to measure the absorption and retention of methylcobalamin versus cyanocobalamin in healthy adults.
SUMMARY
Research shows that cyanocobalamin may be absorbed better in your bodywhile methylcobalamin likely has a higher retention rate. Other studies have found that the differences in absorption and retention are minimal.
When you ingest cyanocobalaminit can be converted to both of the active forms of vitamin B12methylcobalamin and adenosylcobalamin.
Much like methylcobalaminadenosylcobalamin is essential to many aspects of your health.
It’s involved in the metabolism of fats and amino acidsas well as the formation of myelinwhich creates a protective sheath around your nerve cells (9).
Deficiencies in both forms of vitamin B12 can increase your risk of neurological issues and adverse side effects (10).
Both cyanocobalamin and methylcobalamin are reduced to a cobalamin molecule that’s converted to the active forms of this vitamin within the cells of the body (11).
Some researchers recommended treating vitamin B12 deficiencies with either cyanocobalamin or a combination of methylcobalamin and adenosylcobalamin due to distinct properties of these latter two forms (9).
SUMMARY
While they differ in some aspectsboth cyanocobalamin and methylcobalamin can be converted to other forms of cobalamin within the body.
Although distinct differences exist between methylcobalamin and cyanocobalaminboth have beneficial effects on health and can prevent B12 deficiencies (12).
In factone study found that treating seven B12-deficient people with oral methylcobalamin normalized vitamin B12 levels in their blood within just 2 months (13).
Similarlyanother study showed that taking cyanocobalamin capsules for 3 months also increased vitamin B12 levels in 10 people with pernicious anemiaa condition caused by impaired B12 absorption (14).
Both types of the vitamin may also provide other health benefits.
One review of seven studies showed that both methylcobalamin and a vitamin B-complex containing cyanocobalamin were effective in reducing symptoms of diabetic neuropathya complication of diabetes that leads to nerve damage (15).
Additionallyseveral animal studies have found that each form could have neuroprotective effects and may be beneficial in treating conditions that affect your nervous system (16, 17).
SUMMARY
Both methylcobalamin and cyanocobalamin can treat vitamin B12 deficiency. Animal and human studies have found that they could reduce symptoms of diabetic neuropathy and may have neuroprotective effects as well.
If you think you may have a vitamin B12 deficiencytalk to your doctor to determine the best course of treatment.
Howeverif you’re just looking to fill in the nutritional gaps in your dieta vitamin B12 supplement may help.
Cyanocobalamin is a synthetic form of vitamin B12 that can be converted to the natural forms methylcobalamin and adenosylcobalamin.
The body may absorb cyanocobalamin betterwhile methylcobalamin has a higher retention rate.
Both can prevent B12 deficiencybut methylcobalamin should be combined with adenosylcobalamin for best results.
Regardless of which form of vitamin B12 you choosebe sure to combine it with a healthywell-balanced diet to meet your nutritional needs and optimize your health.
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This article is based on scientific evidencewritten by experts and fact checked by experts.
Our team of licensed nutritionists and dietitians strive to be objectiveunbiasedhonest and to present both sides of the argument.
This article contains scientific references. The numbers in the parentheses (123) are clickable links to peer-reviewed scientific papers.
