Vitamin B12 is an essential nutrient for the body, and is needed to protect DNA and RNA, support energy, protect nerve and brain cells, stimulate serotonin production, contribute to red blood cell formation, support immune function, and maintain a positive mood.
There are two forms of vitamin B12 that you’re likely to come across – methylcobalamin and cyanocobalamin. Cyanocobalamin is the most commonly supplemented form of vitamin B12 and is chemically synthesised. Methylcobalamin is found in animal-based foods and is therefore obviously naturally occuring.
Methylcobalamin is rapidly gaining popularity over cyanocobalamin and in all likelihood methylcobalamin will ultimately dominate the industry.
Methylcobalamin has a methyl group (just carbon and hydrogen) while cyanocobalamin contains a cyanide molecule. Although the amount of cyanide in a normal B12 supplement is too small to be harmful, your body will still need to remove and eliminate this compound. As it has no use for the cyano-compound itself, it will set about converting any cyanocobalamin you take into methylcobalamin as soon as possible – it’s the methyl-compound that the human body needs to function properly.
Methylcobalamin the most bio-available form of Vitamin B12, i.e. it is the most readily absorbed. Further to this research has shown that it remains in the body for a longer period of time and at higher levels than cyanocobalamin, which means that your body is supplied with vitamin B12 for longer if you use methylcobalamin than if you use cyanocobalamin.
Methylcobalamin is used primarily in your liver, brain and nervous system, in fact methylcobalamin is the specific form of B12 needed for nervous system health.
Because of methylcobalamin’s importance in nervous system health, it is also an important nutrient for vision. Research has shown that methylcobalamin significantly improves visual accommodation, while cyanocobalamin appears to be ineffective. Visual accommodation is the ability to quickly shift your focus from something nearby to something further away – this is often impaired by activities such as staring at a computer screen for long periods of time.
The most well studied use of methylcobalamin has to do with sleep – although the exact mechanism of action is not yet clear, it is possible that methylcobalamin is needed for the synthesis of melatonin. Research indicates that methylcobalamin can modulate melatonin secretion, enhance light-sensitivity, and normalise circadian rhythm (your body’s 24-hour clock). Because of this, individuals supplementing this form of B12 often report improved quality of sleep, often will require slightly less sleep, and will not uncommonly report that they feel a bit more refreshed when waking in the morning.
One of the primary reactions of methylcobalamin in the body is to convert homocysteine to methionine – high homocysteine levels are undesirable and known to be an indicator of heart disease and stroke risk due to the fact free homocysteine in the blood causes sclerosis of the arteries, putting strain on the vascular system and the heart.
The conversion of homocysteine to methionine reduces the potential for damage because the reaction results in the formation of the super-antioxidant glutathione. Glutathione is the body’s master detoxifier and the body’s main antioxidant, protecting our cells from damage.
* Please note that cyanocobalamin is the form of B12 most used in supplements because it’s the cheapest and while we’ve presented methylcobalamin as the superior form both are excellent at providing nutritionally valuable quantities of Vitamin B12 to the body.
Vitamin B12 is only naturally found in animal products such as organ meats, oily fish, beef and dairy products. If you do not consume those food groups then you are at risk of deficiency – a Vitamin B12 supplement is therefore recommended for vegans and vegetarians, as well as those who suffer from bowel disorders where absorption may be a problem.
The daily recommended intake for Vitamin B12 is 1.5mcg – 2.0mcg/day. However B12 supplements can containing as much as 1000mcg without toxic effect.