Vitamin B12 is fittingly known as the energy vitamin, and your body requires it for a number of vital functions. Among them: energy production, blood formation, DNA synthesis, and myelin formation. Myelin is insulation that protects your nerve endings and allows them to communicate with one another.

If you know or suspect you’re vitamin B12 deficient, you’re not alone. Recent studies from the U.S. Framingham trial show one in four adults in the United States are deficient in this vitally important nutrient, and nearly half the population has suboptimal blood levels.

How You Get Vitamin B12 Deficient

Vitamin B12 is present in natural form only in animal sources of food, which is one of the reasons I advise against a strict vegetarian or vegan diet. There are many well-documented cases of blindness and brain abnormalities in strict vegetarians, resulting from vitamin B12 deficiency.

The older you get the more likely you are to have a vitamin B12 deficiency. The two ways you become deficient are through a lack of vitamin B12 in your diet, or through your inability to absorb it from the food you eat.

I recently visited India, which is primarily a vegetarian based culture. Current studies there show about 80 percent of adults are deficient in vitamin B12.

Vegans and Vegetarians

Vitamin B12 deficiency is extremely common in strict vegetarians and vegans. B12 is not readily available in plants, so if you do not eat meat or animal products you are at risk.

Vitamin B12 is found almost exclusively in animal tissues, including foods like beef and beef liver, lamb, snapper, venison, salmon, shrimp, scallops, poultry and eggs.

The few plant foods that are sources of B12 are actually B12 analogs. An analog is a substance that blocks the uptake of true B12, so your body’s need for the nutrient actually increases.

If you are not a vegan/vegetarian, and are including food sources of B12 in your diet and are still deficient in the vitamin, it is likely due to one of the reasons I’ll discuss later in this report.

Why Vitamin B12 is So Important for Your Health

Vitamin B12, also known by the scientific name cobalamin, is water-soluble. Unlike other water-soluble vitamins, B12 doesn’t exit your body quickly in urine. It is stored in your liver, kidneys and other body tissues. As a result, a deficiency may not show itself for a number of years, depending on your diet and your body’s ability to efficiently absorb B12.

This time lag is a serious concern, because after about seven years of B12 deficiency, irreversible brain damage can result.

Vitamin B12 is a powerhouse micronutrient for a whole host of reasons. Your body needs B12 for:

* proper digestion, food absorption, iron use, carbohydrate and fat metabolism
* healthy nervous system function
* promotion of normal nerve growth and development
* help with regulation of the formation of red blood cells
* cell formation and longevity
* proper circulation
* adrenal hormone production
* healthy immune system function
* support of female reproductive health and pregnancy
* feelings of well-being and mood regulation
* mental clarity, concentration, memory function
* physical, emotional and mental energy

As you can see from this list, your B12 level impacts a number of very important systems in your body — everything from your DNA to how happy you feel. If you think you might be deficient in this vitamin, you need to take steps to get your B12 levels into the healthy range.

I’ll discuss the proper test to determine your B12 blood level as well as the latest information on what constitutes a healthy range a little later in this article.

Symptoms of Vitamin B12 Deficiency

If you don’t have adequate vitamin B12 levels in your bloodstream, you might notice some of the following warning signs:

1. mental fogginess
2. problems with your memory
3. mood swings
4. lack of motivation
5. feelings of apathy
6. fatigue and a lack energy
7. muscle weakness
8. tingling in your extremities

One of the most important functions of vitamin B12 is building the myelin which insulates and protects your nerve endings and allows them to communicate with one another.

If you’re B12 deficient and your myelin is depleted, you can experience health problems as widespread as depression, dementia and even symptoms which mimic multiple sclerosis.


Depression is thought to be linked to a shortage of compounds called monoamines, which are manufactured by your central nervous system. Vitamin B12 helps your body make these compounds. There is also evidence high levels of homocysteine associated with B12 deficiency may promote depression.

Dementia and Alzheimer’s

Research also indicates a B12 deficiency may lead to cognitive problems and reversible dementia in the elderly. This type of treatable dementia differs from Alzheimer’s, however, B12 may play a role in this growing epidemic as well.

A study of over 100 senior volunteers showed older individuals with low levels of vitamin B12 are more apt to suffer from brain atrophy or shrinkage. Brain atrophy is a well-established characteristic of Alzheimer’s disease.


A lack of vitamin B12 can result in a condition called pernicious anemia. Pernicious anemia is characterized by a lack of healthy red blood cells, and a larger size of existing cells.

Since vitamin B12 helps in the formation of red blood cells, a chronic lack of adequate B12 will naturally affect your body’s ability to create red blood cells, eventually leading to anemia. “Pernicious” was the adjective applied to the often fatal condition back in the days before it was understood to be caused by a lack of vitamin B12.

Left untreated, pernicious anemia can do permanent, serious damage to your body. It can increase your risk for heart problems and strokes. It can damage your nerve cells and affect everything from your balance to your sense of smell. It can also cause changes to the surface of your digestive tract, increasing your risk of stomach cancer.

Sleep Problems

If you have trouble sleeping, it could be due to a lack of melatonin in your system. If you’re a regular reader of my newsletter you know the importance I place on adequate good quality sleep for optimum health.

Melatonin is known as the “sleep hormone” and as you age, your body becomes less efficient at producing this chemical.

B12 plays a crucial role in melatonin production, which is another reason it is important to make sure you’re receiving an adequate amount of this vitamin into your blood.

Neurological and Neuropsychiatric Conditions

Inadequate vitamin B12 levels have been linked to many neurological conditions in addition to dementia and Alzheimer’s, including spinal cord disease and peripheral neuropathy.

Peripheral neuropathy is a disease or dysfunction of your peripheral nerves, and can include numbness and tremor, as well as opposite sensations like tingling, pain, itching and pins and needles. Your skin can become hypersensitive to the point where you can’t stand to have anything touching certain areas of your body – clothing and bedding actually cause pain. If your muscles are involved they may feel weak, tired or heavy, and you may experience muscle cramps, tremors, and soreness.

A lack of vitamin B12 might also be implicated in migraine headaches and Parkinson’s disease, both of which are neurological conditions.

Vitamin B12 deficiency has also been linked to psychiatric disorders, which are grouped into the following methods of expression:

1. Mood disturbances … apathy, depression, eating abnormalities, and behavior disturbances which occur specifically at night
2. Hyperactivity … agitation, euphoria, irritability, lack of inhibition, and motor disturbances
3. Psychosis … hallucinations and delusions

Optic neuropathy is another outcome of vitamin B12 deficiency. Long-term, chronic B12 deficiency is known to cause deterioration of the optic nerves, resulting in blindness. This is an irreversible condition.

Cardiovascular and Cerebrovascular Diseases

Cardiovascular and cerebrovascular diseases have a common risk factor – increased homocysteine levels in blood.

Studies show insufficient amounts of folic acid and vitamin B12 can elevate your homocysteine levels, potentially increasing your risk for heart disease and stroke.


We know vitamin B12 plays an important role in DNA synthesis, and its presence in your cells, along with folic acid, helps to alleviate the wear and tear on your genetic material. Damage to DNA is a well-known risk factor for cancer.

Low levels of B12 are specifically linked to increased risk for breast and cervical cancer.

How B12 Deficiency Affects Fertility, Pregnancy and Breastfeeding

Elevated homocysteine levels which result from an inadequate intake of B12 are well-known markers for increased risk of heart problems and stroke. Less known is the fact that high levels of homocysteine are also very dangerous during pregnancy and can lead to complications and birth defects.

Pregnant women with B12 deficiency carry an increased risk of having a baby born with neural tube defects, a class of birth defects affecting the infant’s brain and spinal cord. Spina bifida, which can cause paralysis, is a type of neural tube defect, as is anencephaly, which is fatal.

If you’re planning a pregnancy, it’s absolutely critical to attain a healthy level of vitamin B12 in your blood stream before you conceive. Neural tube defects develop within the first four weeks of fetal life, so if you wait until you’re pregnant to check your B12 levels, it could be too late.

If you’ve had trouble conceiving, or lost pregnancies through miscarriage, you should have your vitamin B12 levels checked. A B12 deficiency has been linked to infertility and repeated miscarriages.

If your diet doesn’t include animal products and you’re breastfeeding, your baby could develop brain abnormalities due to a vitamin B12 deficiency