Vitamin B12, or rather a lack thereof, has been called the "canary in the coalmine" for your future brain health, and recent research has bolstered the importance of this vitamin in keeping your mind sharp as you age.

According to the latest research, people with high levels of markers for vitamin B12 deficiency were more likely to score lower on cognitive tests, as well as have a smaller total brain volume, which suggests a lack of the vitamin may lead to brain shrinkage.

This issue is of paramount importance for many of you reading this for two reasons:

1. Vitamin B12 deficiency is very widespread
2. Your blood level of vitamin B12 is not an adequate marker of whether or not you're deficient, making vitamin B12 deficiency easy to miss

What is Vitamin B12?

Vitamin B12 is a powerhouse micronutrient often known as the "energy vitamin" because it assists in energy production.

Your body relies on the efficient conversion of carbohydrates to glucose -- your body's source of fuel -- to run smoothly, and vitamin B12 plays a major role in that conversion. B12 also enables your body to convert fatty acids into energy. Further, your B12 level impacts a number of very important functions in your body, including:

Problems with Memory, Brain Function Top Signs of Vitamin B12 Deficiency

Mental fogginess and problems with memory are two of the top warning signs that you have vitamin B12 deficiency, and this is indicative of its importance for your brain health.  

In addition to the latest Neurology study, which found more signs of shrinkage of brain tissue among those with low vitamin B12, a Finnish study published in Neurology last year found that people who consume foods rich in B12 may reduce their risk of Alzheimer's in their later years. For each unit increase in the marker of vitamin B12 (holotranscobalamin) the risk of developing Alzheimer's was reduced by 2 percent. Research also shows that supplementing with B vitamins, including B12, helps to slow brain atrophy in elderly people with mild cognitive impairment (brain atrophy is a well-established characteristic of Alzheimer's disease).

What Causes B12 Deficiency?

Vitamin B12 is the largest vitamin that we know of. Because of its large size, it is not easily absorbed passively like most supplements. Because of this, many, if not most oral B12 supplements are worthless and do NOT work. Vitamin B12 requires a complex system in your body involving intrinsic factor to bind to it so it can be actively absorbed in the end of your small intestine (terminal ileum). As you grow older the ability to produce intrinsic factor decreases and cause a deficiency state.

Studies from the U.S. Framingham trial show one in four adults are deficient in vitamin B12, and nearly half the population has suboptimal blood levels. If you eat an all vegetarian or vegan diet, vitamin B12 is one of the nutrients your body is most likely deficient in, as it is naturally present in foods that come from animals, including meat, fish, eggs, milk and milk products. However, there are many other causes of B12 deficiency as well, including:

• Food-Cobalamin Malabsorption Syndrome: This condition results when your stomach lining loses its ability to produce intrinsic factor, a protein that binds to vitamin B12 and allows your body to absorb it into your bloodstream at the furthest point of your small intestine.

Intrinsic factor is a protein made by your stomach. It grabs onto the B12 molecule and together they move through your stomach to your small intestine. When they reach the end of your small intestine, the intrinsic factor is absorbed first, pulling the B12 with it into the cells of your large intestine, where they are absorbed for use by the rest of your body.

• Increasing Age: Intrinsic factor diminishes as you age, and this means it's virtually impossible to get B12 from your diet. This also means the older you get, the more likely you will need to supplement B12.
• Use of the drug metformin for Type 2 diabetes: Use of metformin (brand names include Glucophage, Glucophage XR, Fortamet, Riomet, and Glumetza) may inhibit your B12 absorption, especially at higher doses.
• Coffee consumption: Four or more cups of coffee a day can reduce your B vitamin stores by as much as 15 percent.
• Use of antacids: The use of antacids or anti-ulcer drugs will lower your stomach acid secretion and decrease your ability to absorb vitamin B12. Stomach acid (hydrochloric acid) is a crucial ingredient in your body's ability to absorb B12. If you're taking a medication specifically designed to reduce the amount of stomach acid you produce, your body's ability to use vitamin B12 from the food you eat or the supplements you take will be significantly compromised.
• Gastric bypass surgery
• Exposure to nitrous oxide (laughing gas)

Why a Blood Test May Not be Enough to Detect Deficiency

Blood tests for vitamin B12 deficiency aren't as clear cut or helpful as they are for other nutritional deficiencies. Standard tests to assess vitamin B12 concentrations are limited because the clinical severity of vitamin B12 deficiency is unrelated to vitamin B12 concentrations. As researchers concluded in Neurology:

"Concentrations of all vitamin B12-related markers, but not serum vitamin B12 itself, were associated with global cognitive function and with total brain volume."

So generally speaking, you can use the following recommendations to screen for vitamin B12 deficiency:

• If your vitamin B12 concentration is less than 150 pmol/L, you are considered B12 deficient and you and your health care practitioner should take steps to determine the underlying cause(s) and treatment.
• If your B12 concentration is between 150 and 200 pmol/L, your serum MMA (Methylmalonic Acid) level should be determined to identify whether your situation requires more investigation and treatment. Research suggests elevated levels of MMA (a natural compound found in your body) are an indicator for vitamin B12 deficiency.

However, if you suspect or are concerned you are vitamin B12 deficient, a more practical option may be to simply supplement your diet with B12 and see if your symptoms improve.

B12 is available in its natural form only in animal food sources. These include seafood, beef, chicken, pork, milk, eggs. If you don't consume enough of these animal products (and I don't recommend consuming seafood unless you know it is from a pure water source) to get an adequate supply of B12, or if your body's ability to absorb the vitamin from food is compromised, vitamin B12 supplementation is completely non-toxic and inexpensive, especially when compared to the cost of laboratory testing.

In fact, the first treatment most doctors and other health care experts will suggest upon receiving B12 deficiency lab test results is supplementation with vitamin B12. I recommend either an under-the-tongue fine mist spray, as this technology helps you absorb it into the fine capillaries under your tongue. This delivery system bypasses the intrinsic factor problem and is much easier, safer and less painful than having your doctor inject you with a vitamin B12 shot.

Signs and Symptoms to Watch For

Besides the above-mentioned mental fogginess and memory problems, there are actually a wide range of symptoms of vitamin B12 deficiency, from mild to severe, which can affect your body, mind and mood. In general, the signs are:

• Fatigue, lack of energy, muscle weakness, tingling in your extremities
• Mental fogginess or problems with your memory, trouble sleeping
• Mood swings, especially feelings of apathy or lack of motivation

Other symptoms of long-term, chronic B12 deficiency are included in the chart above. Even though vitamin B12 is water-soluble, it doesn't exit your body quickly like other water-soluble vitamins. B12 is stored in your liver, kidneys and other body tissues, and as a result, a deficiency may not show itself for a number of years until you finally run out of this naturally stored internal source of the vitamin.

This time lag in seeing symptoms of a B12 deficiency is a serious concern, because after about seven years of deficiency, irreversible brain damage can potentially result. So if you are suffering from any of the symptoms above it makes sense to take steps to increase your levels to protect your long-term brain, and overall, health.

IMPORTANT B12 Summary: Please Remember…

If you believe you need a vitamin B12 supplement, don't hesitate to take one. They are very safe and there are virtually no known side effects. However, avoid oral B12 supplements as they will not be easily absorbed. You can take an injection or do a far easier sublingual (under your tongue) spray that allows the large B12 structure to bypass your intestine and be absorbed directly into your blood stream, allowing you to benefit immediately.  

Source:  Science Daily September 27, 2011

Source:  Science News September 27, 2011

Source:  Neurology September 27, 2011;77(13):1276-82.