Injectable vitamin B12 is available as a supplement in several forms, each with it’s own advantages and disadvantages. Learning about each will help you decide which of these forms is best for you. As always, you should consult your health professional when making health related decisions.
The different forms of vitamin B12 are collectively called cobalamins because they share in common the mineral cobalt. These various cobalamins are converted by your body into methylcobalamin and 5-deoxyadenosylcobalamin, the forms of vitamin B12 that are active in human metabolism.
The Different Forms of Vitamin B12 Cobalamin
Injectable vitamin B12 supplements are available in 3 common types. Existing evidence does not suggest any differences among forms with respect to absorption or bioavailability.
Cyanocobalamin – A Well-documented, United States FDA approved, inexpensive and stable source of vitamin B12 that the human body naturally converts into methylcobalamin. It comes in both an oral and an injectable form that is safe, highly effective and fast-acting. The injectable version may be delivered intramuscularly (IM) or subcutaneously (SQ). Cyanocobalamin is most notable because the cobalamin is bonded to a cyanide molecule. This concerns some people, but is easily detoxified by most except those with particular health issues and heavy smokers. As an injectable cyanocobalamin is nearly painless, widely available and is the least expensive.
Hydroxocobalamin – Another synthetic version of B12, favored in Europe. Although not United States FDA approved, it is a widely accepted form of treatment and the World Health Organization recommends it. The primary method of delivery is via intramuscular (IM) injection, but these can be painful. Hydroxocobalamin is recommended for heavy smokers and is actually considered a treatment for cyanide poisoning. If approved by the FDA this form could become much more common resulting in lower cost.
Methylcobalamin – Immediately available to the body (does not require conversion) and is often referred to as an active form of B12. This form is better suited for heavy smokers and people with blood detoxification health issues. Unfortunately injectable methylcobalamin is the least stable type of B12 requiring refrigeration and having a typical shelf life of 1-2 months. The inconvenience is also reflected in higher costs for this injectable.
Which Form of Vitamin B12 Should You Choose?
When choosing which of the cobalamins is right for you should consider their effectiveness, any health concerns you have, convenience and cost.
For most people the injectable form cyanocobalamin is safe, effective and the best value. It has a longer shelf life than methylcobalamin and is less painful and more widely available than the injectable version of hydroxocobalamin.
Michael Greger M.D. at Nutitionfacts.org had this to say about which type of vitamin B12 is best:
B12 is so cheap to produce that supplement manufacturers try to come up with all sorts of fancy ways to “add value” to products so they can charge $30 a bottle. Unless you’re a smoker, have kidney failure, or base your diet around cassava root, cyanocobalamin should be fine.
If you are a heavy smoker or have health problems that impair your ability to detoxify you should consider the other options: hydroxocobolamin or methylcobolamin. (Smokers might also want to reconsider smoking, but that is a topic for another article…)
Hydroxocobalamin may one day become the B12 of choice by the health community because it does not have the health complications for some people that cyanocobalamin has and is more convenient than methylcobolamin.
Consult your health professional before using any supplements.
Some Background on Vitamin B12 and B12 Supplementation
According to the National institute of Health (NIH), “Vitamin B12 is required for proper red blood cell formation, neurological function, and DNA synthesis.” It helps keep nerve cells healthy.
Although naturally present in in animal products, like fish, meat, poultry, eggs, milk, and milk products, many people do not digest proper levels of the important nutrient or it may be processed out of the fast foods that most people consume on a regular basis. Vitamin B12 is almost never found plants so vegetarians especially should consider adding a Vitamin B12 supplement to their diet. Most multiple vitamins include at least some level of vitamin B12 AKA Folic Acid and it is available as a stand-alone in pills, sub lingual (dissolved under the tongue) and injectable forms.
The NIH describes the benefits in detail, outlines recommended daily intake, harmful effects of too little Vitamin B12 in the diet along with cautionary suggestions for people who decide to supplement their diets with over the counter products.
Symptoms of Vitamin B12 Deficiency
People with low levels of Vitamin B12 may experience tiredness, weakness, have poor appetites, suffer from constipation, have megoplastic anemia and may have nerve related issues like numbness and tingling in the hands and feet (peripheral neuropathy). Both children and adults may have poor balance, depression, confusion, dementia and soreness in their mouths due to a lack of Vitamin B12.
Sources
United States National Institutes of health Vitamin B12 Dietary Supplement Fact Sheet
United States National Institutes of health Vitamin B12 Consumer Fact Sheet
US National Library of Medicine, Cyanocobalamin
US National Library of Medicine, Hydroxocobalamin
US National Library of Medicine, Effects of smoking on metabolism and excretion of vitamin B12
Michael Greger M.D., Nutritionfacts.org
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Effects of Aging on Vitamin B12 Absorption - A decrease in B12 levels is commonly seen with increased age. Deficiencies in B12 can cause or worsen cognitive difficulties, sometimes mistaken for memory loss or early dementia in seniors.
I do eat cassava flour foods, like tortillas and chips. What is the concern with cyanocobalamin if you consume cassava?