What is Vitamin B12?

Vitamin B12, also known as cobalamin, is a water-soluble vitamin that plays a crucial role in various bodily functions, including DNA synthesis, red blood cell formation, and nerve system functioning. It is one of the eight B vitamins and is vital for brain health and the production of energy.

How does it work for medicinal purposes?

Vitamin B12 works in several ways for medicinal purposes:

• DNA Synthesis: It is essential for the production of DNA during cell division, particularly in tissues where cells are rapidly dividing, such as bone marrow.
• Red Blood Cell Formation: It is crucial for the proper formation, development, and functioning of red blood cells, helping to prevent anemia.
• Nervous System Support: It supports the maintenance of nerve cells and helps to produce the protective sheath around nerves, known as the myelin sheath.
• Homocysteine Metabolism: It plays a role in converting homocysteine, a type of amino acid in the blood, into methionine, which is necessary for the body.

Active Ingredients Important for Its Medicinal Properties

The active ingredient in Vitamin B12 is cobalamin. There are various forms of cobalamin, including cyanocobalamin, methylcobalamin, and hydroxocobalamin, each of which has a slightly different effect in the body. Methylcobalamin is the most bioavailable form of Vitamin B12 and is the form that is most easily absorbed and utilized by the body.

Forms it Comes In

Vitamin B12 is available in several forms, including:

• Oral Supplements: Tablets or capsules
• Sublingual Supplements: Tablets or lozenges that dissolve under the tongue
• Injections: Administered directly into the muscle, usually for those with absorption issues
• Nasal Spray: A form that can be sprayed into the nose
• Liquid: For those who have difficulty swallowing pills

When was it first used for medicinal purposes?

Vitamin B12 was first isolated in 1948 by two separate groups of scientists, and its medicinal uses have been explored since then, particularly in the treatment of pernicious anemia.

What if I have an imbalance or deficiency?

A lack of Vitamin B12 can lead to various symptoms and conditions, including:

• Anemia: Leading to fatigue, weakness, and pale skin.
• Neurological Changes: Such as numbness and tingling in the hands and feet.
• Memory Loss: Particularly in older adults.
• Difficulty Walking: Due to nerve damage.
• Mood Changes: Including depression and irritability.
• Vision Loss: In severe cases, due to damage to the optic nerves

Summary

Vitamin B12, or cobalamin, is a crucial water-soluble vitamin integral for red blood cell formation, DNA synthesis, and proper neurological function. The active ingredient, cobalamin, exists in various forms, including cyanocobalamin and methylcobalamin. It ensures the proper development and functioning of the brain and nerve cells, aids in converting homocysteine to methionine (a necessary amino acid), and plays a critical role in energy production. A deficiency in Vitamin B12 can lead to anemia, neurological disorders, and elevated homocysteine levels, which is a risk factor for cardiovascular diseases. Historically, Vitamin B12 was first isolated in 1948 and has since been used medicinally to treat pernicious anemia and other conditions related to B12 deficiency.

Historical Use and Discovery

Vitamin B12 was first isolated in 1948, simultaneously by two groups of scientists: Karl Folkers and his team at Merck and E. Lester Smith

What does Vitamin B12 (Cobalamin) help with?

Vitamin B12, also called cobalamin, is a nutrient your body cannot make on its own. It comes mostly from meat, fish, eggs and dairy. It is well established that your body needs it to build red blood cells and keep nerves healthy.

• Anemia caused by low B12
  Strong evidence — long-standing, consistent human treatment data; no trial sizes on file. When B12 runs low, red blood cells grow large and oddly shaped. Doctors call this megaloblastic anemia. Blood counts came back up reliably in patients given B12 pills or shots.
  Evidence grade A · Traditional tier T0
• Filling the gap in a vegan or vegetarian diet
  Strong evidence — consistent human studies of blood levels in plant-based eaters. B12 is found almost only in animal foods. Studies found a very high rate of low levels in vegans over time. Most guidance treats a B12 source as essential, not optional, for vegans, and wise for vegetarians who rarely eat dairy or eggs.
  Evidence grade A · Traditional tier T0
• High homocysteine on a blood test
  Strong evidence — repeated human trials that measured blood homocysteine. Homocysteine is an amino acid that builds up when B12 is low. In trials, B12 taken with folate and B6 lowered high homocysteine levels. Whether that drop prevents heart events is still being studied.
  Evidence grade A · Traditional tier T0
• Tingling, numbness or burning in hands and feet
  Good evidence — human studies in people with a confirmed shortage. B12 is well established to help keep the myelin coat around nerve fibres intact. When it runs low, nerves misfire, and people feel tingling or burning. Caught early, these symptoms eased or cleared; caught late, recovery was slower and often partial.
  Evidence grade B · Traditional tier T0
• Low mood and depression, alongside treatment
  Good evidence — clinical trials of B12 added to antidepressant drugs. Low B12 turns up more often in people with depression. In clinical trials, adding B12 to drug treatment improved outcomes more than the drug alone. Trial sizes and doses are not recorded in our file.
  Evidence grade B · Traditional tier T0
• Fatigue and low energy
  Good evidence — human studies in people whose levels were low. B12 is well established to be needed to turn food into cell energy. When it is low, red blood cells carry less oxygen, and people feel truly worn out. In people with a shortage, energy often improved within a few weeks of treatment.
  Evidence grade B · Traditional tier T0
• Brain fog, memory slips and thinking as you age
  Early evidence — small human studies in deficient people, plus brain-scan trials in at-risk elders. People with mildly low B12 often report slow thinking and memory gaps. In studies of such people, thinking test scores improved after levels were restored. In older adults with low-normal B12 and high homocysteine, brains shrank faster, and B12 slowed that shrinking.
  Evidence grade C · Traditional tier T0
• Mouth ulcers and a sore, swollen tongue
  Early evidence — clinical reports in patients with low B12; no trial sizes on file. A red, sore, swollen tongue is a classic early sign of low B12. Repeat mouth ulcers show up too. In clinic reports, both cleared once levels came back to normal.
  Evidence grade C · Traditional tier T0
• Poor sleep and an off body clock
  Evidence doesn't support this — small and mixed human studies. Some studies linked B12 to better sleep quality and steadier sleep-wake timing. Most of those people were either low in B12 or had delayed sleep phase. The findings were mixed, so this is not a settled result.
  Evidence grade D · Traditional tier T0

What Vitamin B12 (Cobalamin) has not been shown to do

• It has not been shown to lift energy in people whose B12 level is already normal.
• Lowering homocysteine with B12 has not been shown to prevent heart attacks or strokes.
• It has not been shown to fully undo nerve damage that went untreated for a long time.
• It has not been shown to prevent dementia in older people with normal B12 levels.
• It has not been shown to work as a sleep aid for people with normal B12.

How to read this:

Grades run from A down to insufficient. A means many good human trials agree. B means at least one solid human trial. C means small or mixed human studies. D means the human evidence is weak. Insufficient means no human study is on file. This page reports what studies found. It is not medical advice, and it is not a claim that B12 treats any illness. Most of the strong evidence here is about fixing a shortage, so a blood test comes first. Talk with a clinician before you start.

What can Vitamin B12 (Cobalamin) help prevent?

• Neural tube defects in pregnancy (when combined with folate)
• Megaloblastic anemia in people with absorption issues or low dietary intake
• Accelerated brain atrophy in older adults with low B12 and elevated homocysteine
• Peripheral neuropathy in long-term metformin users

Foods Rich in Vitamin B12

1. Beef Liver
2. Clams
3. Fish
4. Meat
5. Poultry
6. Eggs
7. Dairy Products
8. Fortified Cereals
9. Fortified Nutritional Yeasts
10. Fortified Non-Dairy Milk

Possible Side Effects

Vitamin B12 is generally well tolerated. However, some possible side effects include:

• Allergic Reactions: Rare but possible.
• Mild Diarrhea
• Swelling
• Skin Rash
• Dizziness
• Headache

Recommended Daily Dose

• Adult Men: 2.4 mcg
• Adult Women: 2.4 mcg
• Pregnant Women: 2.6 mcg
• Breastfeeding Women: 2.8 mcg

How Many Days Does it Take to Work?

The time it takes for Vitamin B12 to work depends on the condition being treated, but improvements can often be felt within a few days to weeks.

Best Time of Day to Take It

There is no specific time of day that is universally best for taking Vitamin B12; it can be taken at any time, according to personal preference and tolerance.

With or Without Food

Vitamin B12 can be taken with or without food. However, taking it with food may enhance its absorption, especially when taken along with other B vitamins.