B12 is an essential vitamin with roles throughout the body. It is needed for the development and maintenance of a healthy nervous system, the production of DNA and formation of red blood cells.
A severe B12 deficiency results in pernicious anemia, which can be picked up by a blood test. But the less dramatic symptoms of a B12 deficiency may include muscle weakness, fatigue, shakiness, unsteady gait, incontinence, low blood pressure, depression and other mood disorders, and cognitive problems like poor memory.
Labs differ in what they consider normal, but most authorities say a deficiency occurs when B12 levels in adults fall below 250 picograms per milliliter of blood serum. In Japan, the lowest acceptable level for vitamin B12 is 550 pg/mL.
Like all B vitamins, B12 is water-soluble, but the body stores extra B12 in the liver and other tissues. Even if dietary sources are inadequate for some time, a serum deficiency may not show up for years.
This vitamin occurs naturally in a number of food types derived from animals such as eggs, milk, meat, and fish. It is not easily absorbed by the human body from plant foods.
It is actively present in the human body in the form of Adenosylcobalamin and Methylcobalamin.
Synthetic forms of the vitamin are produced from bacterial enzymes and include Cyanocobalamin and Hydroxocobalamin.
You can find B12 supplements available via Injections, Sublingual (a pill that is placed to dissolve under the tongue to diffuse into the blood through the tissue in that area), Nasal Spray, Liquid, Skin Patches, or Pill.
Consider the source (form of B12) of the supplement type you choose. Many articles recommend Methycobalamin.
Hydroxocobalamin – Synthetic form. It is produced by bacteria (in a lab). It can stay longer in the body so there’s no urgency of frequent injections. This can be an aid in treating cyanide poisoning. It doesn’t hesitate to have contact with cyanide molecule, so it evolves into cyanocobalamin to be able to be disposed outside the body in form of urine.
Cyanocobalamin – Synthetic form. This is the most common injection form of B12. Its popularity is due to its sturdy structure of its molecule. Its durability makes it resistant to any air-damage. Once it is ingested, it turns into cyanide. The little cyanide portion will pass out from the body and cyanocobalamin will be converted into methycobalamin. That process will be impossible when there’s toxin and heavy metals in the liver that mostly happen among smokers.
Methycobalamin – Natural form. Dwells actively within the body. It can be bio-available among smokers as it had been replaced by a methyl group.
Adenosylcobalamin – Natural form. It has an active B12 molecule that can be found in the body.
Folic acid can cover up vitamin B12 deficiency. It is best to check your vitamin B12 levels before you start taking folic acid.
Potassium supplements can reduce absorption of vitamin B12 in some people.
Early research suggests that vitamin C supplements can destroy dietary vitamin B12. To stay on the safe side, take vitamin C supplements at least 2 hours after meals.
Please read the NY Times article in full. It tells a story of a woman diagnosed with early Alzheimer’s due to her poor memory then proven false with a B12 blood test. Her levels of B12 were below normal, symptoms of this deficiency mimicked the onset of Alzheimer’s.
Quoted from Sources:
nytimes.com – Vitamin B12 Deficiency Symptoms can Mimic
wikipedia.org – Vitamin B12 Deficiency
www.nlm.nih.gov/medlineplus – What is B12
articlestatus.com – B-12 injection
wisegeek.com – Adenosylcobalamin