Vitamin B_¹² is a member of the vitamin B complex group of vitamins. It is an extremely important vitamin necessary for the manufacture of red blood cells, the maintenance of a healthy nervous system for the production of DNA (your genetic material) and for growth and development in children.

SOURCES OF B_¹²

Neither plants nor animals makes vitamin B_¹². It is made exclusively by bacteria. Vegetarian animals (e.g. cows) get their B_¹² from the bacteria in their intestines that make it. Then that animal can itself become a source of vitamin B_¹². Other animals get their vitamin B_¹² from eating foods containing vitamin B_¹². Plant foods do not contain vitamin B_¹², except when they contain certain bacteria or are fortified with added vitamin B_¹².

Unfortified sources of vitamin B_¹² are meat, liver, some shellfish, dairy products and eggs. Researchers have looked for vitamin B_¹² in fermented soy products like tempeh, miso and tamari and in seaweed and algae such as spirulina. Analysis found no significant B_¹². Some seaweed do contain B_¹²-like substances, but these may not be active.

Thus some experts contend that B_¹² naturally present in plant foods may not be a very reliable source. However, many vegetarian foods are supplemented with B_¹². These include soy shakes, veggie burger mixes, textured vegetable protein, soy milks, yeast extracts and breakfast cereals. Vegans should, therefore, include B_¹²-fortified foods in their diet.

B_¹² DEFICIENCY

B_¹² deficiency results in a special kind of anaemia called pernicious anaemia. Symptoms include excessive tiredness, breathlessness, fatigue, pallor, and poor resistance to infection. Other symptoms can include a smooth, sore tongue and menstrual disorders.

B_¹² is also important in maintaining the nervous system. Nerves are insulated with a fatty sheath called myelin. B_¹² plays a vital role in the maintenance of myelin. Prolonged B_¹² deficiency can lead to nerve degeneration and severe neurological damage.

Vitamin B_¹² reduces the blood levels of a toxic substance called homocysteine. Homocysteine has emerged as a bigger risk factor for heart disease and stroke than cholesterol, and is also connected to other diseases such as arthritis, Alzheimer's and diabetes.

Those who can't get to sleep at night may need vitamin B_¹². Studies show that B_¹² acts directly on the pineal gland in the brain to provoke a faster release of the hormone melatonin. Melatonin has been called 'the sleep hormone' because of its effects on sleep.

ROOTS OF DEFICIENCY

Failure to absorb B_¹² from the intestine is a major issue. Vitamin B_¹² in food is bound to protein. Hydrochloric acid in the stomach is needed to release vitamin B_¹² from the proteins in the food. Then B_¹² requires a special substance from the stomach called intrinsic factor for it to be absorbed. People who do not produce intrinsic factor or enough acid do not absorb B_¹² from food or multivitamin tablets.

Otherwise, diet, age and drugs are the prime culprits behind B_¹² deficiency. Tagamet, Prilosec and other drugs that inhibit acid secretion can cause B_¹² deficiency. Anyone who chronically takes drugs for stomach ulcers, heartburn or acid reflux may be inducing B_¹² deficiency.

Your levels of B_¹² decrease every year as you age. Age-related deficiency is associated with hearing loss, memory impairment and psychiatric disorders, along with heart disease and stroke.

MY RECOMMENDATIONS

CHECK YOUR BLOOD - At your next check-up, ask your doctor to check your B_¹² and homocysteine levels. I have been amazed at how many people are walking around with low, normal or abnormal B_¹² levels. You want you levels to be high.

TAKE B_¹² SUPPLEMENTS - There are different levels at which you can supplement with vitamin B_¹².

A quality multivitamin will contain some B_¹², which if you can absorb well, will be adequate. Higher potency forms of supplements may be needed, however, in other circumstances.

High-potency B complex tablets contain higher levels of B_¹².

Sublingual B_¹² is a powerful way to take B_¹² as the tablet is placed under the tongue and absorbed through the membranes directly into the bloodstream. This will bypass the stomach problems discussed above.

Vitamin B_¹² injections are another option. I often prescribe weekly B_¹² injections for certain conditions.

Methylcobalamin is the neurologically active form of vitamin B_¹². Studies have shown that high doses of methylcobalamin are effective in nerve-cell regeneration without any toxic effects. Diabetic neuropathy and other nerve disorders respond well the this form of vitamin B_¹².

Finally, vitamin B_¹² is extremely safe, even in very high dosages, and is relatively inexpensive. So keep your B_¹² levels high.

Email Dr. Tony Vendryes at info@anounceofprevention.org, log on to www.anounceofprevention.org, or listen to 'An Ounce of Prevention' on Power 106FM on Fridays and Saturdays at 8:00 p.m.