Health Benefits of Vitamin B12

Alcohol's Effects on B-12 Absorption
 
Drinking alcohol, even in moderation, can have profound effects on the way your body absorbs vitamin B-12 and, if you are deficient in this vitamin, your health may suffer. It is important to be aware of how your body absorbs vitamin B-12, as this knowledge can help you make an informed decision about the amount of alcohol you consume.

Vitamin B-12 is an essential nutrient you need for two enzymatic reactions in the body. If you are deficient in vitamin B-12, these enzymatic reactions cannot occur, which could lead to a buildup of a compound called homocysteine. An increase in homocysteine is associated with an increased risk of heart attack and stroke.

Low vitamin B12 levels increase the risk of fractures in older men

Older men who have low levels of vitamin B12 have a higher risk of having fractures. These are the findings of researchers at the Sahlgrenska Academy as a part of an international study of a total of 1000 older men.

Osteoporosis is one of the world's most widespread diseases, and intensive research is under way worldwide to identify its causes and to be able to prevent fractures.

In an extensive study, researchers at the Sahlgrenska Academy at the University of Gothenburg can now show that low levels of vitamin B12 in the blood increases the risk of fractures in older men.

International research project

This study is a part of an international research project initiated by the National Institutes of Health (NIH) in the US and comprises 11,000 men in total. In their part of the study, the Gothenburg researchers studied 1,000 Swedish men, MrOS Sweden, with an average age of 75, and used various methods to analyze the blood concentrations of the B vitamins B12 and folate, which are found in our food naturally.

Higher fracture risk

The results show that the risk of suffering a fracture six years later was higher among men who had low B12 levels at the beginning of the study than men with normal B12 levels. In the quartile with the lowest B12 content, the risk was elevated by approximately 70 percent compared with the others. The risk increase pertained primarily to fractures in the lumbar region, where the risk increase was up to 120 percent.

"The higher risk also remains when we take other risk factors for fractures into consideration, such as age, smoking, BMI, BMD (bone mineral density), previous fractures, physical activity, the D-vitamin content in the blood and calcium intake," says Catharina Lewerin, researcher at the Sahlgrenska Academy.

Does this mean that older men can prevent fractures by eating more vitamin B12?

"It has not been scientifically established, but such studies are under way, including one large Dutch study where older individuals over the age of 65 are treated with both vitamin B12, folic acid and vitamin D to investigate the occurrence of fractures.

"Right now, there is no reason to eat more vitamin B12, but rather treatment shall only be applied in confirmed cases of deficiencies and in some cases to prevent deficiencies. For anyone who wants to strengthen their bones and prevent fractures, physical activity 30 minutes a day and quitting smoking is good self care," says Catharina Lewerin.

New method

In this study, the researchers used a relatively new method called holotranscobalamin, which measures the amount of vitamin that is taken up in the cells, which is considered to be a more sensitive test for B12 deficiency.

The article was published online December 2013 in Osteoporosis International.

Acid-Reflux Drugs Tied to Lower Levels of Vitamin B-12

People who take certain acid-reflux medications might have an increased risk of vitamin B-12 deficiency, according to new research.

Taking proton pump inhibitors (PPIs) to ease the symptoms of excess stomach acid for more than two years was linked to a 65 percent increase in the risk of vitamin B-12 deficiency. Commonly used PPI brands include Prilosec, Nexium and Prevacid.

Researchers also found that using acid-suppressing drugs called histamine-2 receptor antagonists -- also known as H2 blockers -- for two years was associated with a 25 percent increase in the risk of B-12 deficiency. Common brands include Tagamet, Pepcid and Zantac.

"This study raises the question of whether or not people who are on long-term acid suppression need to be tested for vitamin B-12 deficiency," said study author Dr. Douglas Corley, a research scientist and gastroenterologist at Kaiser Permanente's division of research in Oakland, Calif.

Corley said, however, that these findings should be confirmed by another study. "It's hard to make a general clinical recommendation based on one study, even if it is a large study," he said.

Vitamin B-12 is an important nutrient that helps keep blood and nerve cells healthy, according to the U.S. Office of Dietary Supplements (ODS). It can be found naturally in meat, fish, poultry, eggs, milk and other dairy products. According to the ODS, between 1.5 percent and 15 percent of Americans are deficient in B-12.

Although most people get enough B-12 from their diet, some have trouble absorbing the vitamin efficiently. A deficiency of B-12 can cause tiredness, weakness, constipation and a loss of appetite. A more serious deficiency can cause balance problems, memory difficulties and nerve problems, such as numbness and tingling in the hands or feet.

Stomach acid is helpful in the absorption of B-12, Corley said, so it makes sense that taking medications that reduce the amount of stomach acid would decrease vitamin B-12 absorption.

More than 150 million prescriptions were written for PPIs in 2012, according to background information included in the study. Both types of medications also are available in lower doses over the counter.

Corley and his colleagues reviewed data on nearly 26,000 people who had been diagnosed with a vitamin B-12 deficiency and compared them to almost 185,000 people who didn't have a deficiency.

While 12 percent of people with a vitamin B-12 deficiency had taken PPIs for more than two years, 7.2 percent of those without a deficiency had taken the medications long-term.

Of those with a deficiency, 4.2 percent took an H2 blocker for two years or longer, while 3.2 percent of those without a deficiency took the drugs for two years or more.

The risk of developing a vitamin B-12 deficiency was 65 percent higher for the long-term PPI users and 25 percent higher for those taking H2 blockers, according to the study.

People who took higher doses were more likely to develop a vitamin B-12 deficiency. People who took an average of 1.5 PPI pills per day had almost double the risk of developing a deficiency compared to those who averaged 0.75 pills per day, the study found.

Women had a greater risk of deficiency than men, and people younger than 30 taking these medications had a greater risk of developing a deficiency than older people, according to the study.

The risk of vitamin B-12 deficiency decreases when you stop taking the medications, but doesn't disappear completely, Corley said.

The study's findings were published in the Dec. 11, 2013 issue of the Journal of the American Medical Association. Although the study found an association between taking acid-reflux drugs long-term and having a higher risk of a B-12 deficiency, it didn't establish a cause-and-effect relationship.

If you're taking acid-suppressing medications, Corley said, "our study doesn't recommend stopping those medications, but you should take them at the lowest effective dose." And people shouldn't start taking vitamin B-12 supplements on their own, but should discuss it with their doctor, he said.

One expert had concerns about how frequently acid-suppressing drugs are used.

"This study found an adverse effect associated with taking these drugs," said Victoria Richards, an associate professor of medical sciences at the Frank H. Netter M.D. School of Medicine at Quinnipiac University, in Hamden, Conn. "It's also concerning that these drugs are used at such a high rate. Why do so many people have the need to suppress acid so much?"

The bottom line, Richards said, is that if you are having any symptoms of vitamin B-12 deficiency and you've been taking these medications, talk to your doctor about whether you should be tested for a deficiency. Tell your doctor if you've been taking over-the-counter acid-suppressing medications, so your doctor can properly evaluate your risk.

Low Vitamin B12 Levels May Lead to Brain Shrinkage, Cognitive Problems

Older people with low levels of vitamin B12 in their blood may be more likely to lose brain cells and develop problems with their thinking skills, according to a study published in the September 27, 2011, print issue of Neurology®, the medical journal of the American Academy of Neurology. Foods that come from animals, including fish, meat, especially liver, milk, eggs and poultry, are usually sources of vitamin B12.

The study involved 121 people age 65 and older living on the south side of Chicago. Their blood was drawn to measure levels of vitamin B12 and B12-related metabolites that can indicate a B12 deficiency. The participants also took tests measuring their memory and other cognitive skills. An average of four-and-a-half years later, MRI scans of the participants’ brains were taken to measure total brain volume and look for other signs of brain damage.

Having high levels of four of five markers for vitamin B12 deficiency was associated with having lower scores on the cognitive tests and smaller total brain volume.

 

“Our findings definitely deserve further examination,” said study author Christine C. Tangney, PhD, of Rush University Medical Center in Chicago. “It’s too early to say whether increasing vitamin B12 levels in older people through diet or supplements could prevent these problems, but it is an interesting question to explore. Findings from a British trial with B vitamin supplementation are also supportive of these outcomes.”

On the cognitive tests, the scores ranged from -2.18 to 1.42, with an average of 0.23. For each increase of one micromole per liter of homocysteine—one of the markers of B12—the cognitive scores decreased by 0.03 standardized units or points.

Vitamin B12 May Reduce Risk of Alzheimer's Disease

A new study shows that vitamin B12 may protect against Alzheimer's disease, adding more evidence to the scientific debate about whether the vitamin is effective in reducing the risk of memory loss.

The research will be published in the October 19, 2010, issue of Neurology®, the medical journal of the American Academy of Neurology.

"Our findings show the need for further research on the role of vitamin B12 as a marker for identifying people who are at increased risk of Alzheimer's disease," said study author Babak Hooshmand, MD, MSc, with Karolinska Institutet in Stockholm, Sweden. "Low levels of vitamin B12 are surprisingly common in the elderly. However, the few studies that have investigated the usefulness of vitamin B12 supplements to reduce the risk of memory loss have had mixed results."

For the seven-year study, researchers took blood samples from 271 Finnish people age 65 to 79 who did not have dementia at the start of the study. During that time, 17 people developed Alzheimer's disease. Blood samples were tested for levels for homocysteine, an amino acid associated with vitamin B12, and for levels of the active portion of the vitamin, called holotranscobalamin. Too much homocysteine in the blood has been linked to negative effects on the brain, such as stroke. However, higher levels of vitamin B12 can lower homocysteine.

The study found that for each micromolar increase in the concentration of homocysteine, the risk of Alzheimer's disease increased by 16 percent, whereas each picomolar increase in concentration of the active form of vitamin B12 reduced risk by two percent. The results stayed the same after taking into account other factors, such as age, gender, education, smoking status, blood pressure and body mass index. The addition of folate did not appear to raise or lower the risk of Alzheimer's disease.

"More research is needed to confirm these findings before vitamin B12 should be used solely as a supplement to help protect memory," said Hooshmand.

In an online posting in July, David G. Schardt, the senior nutritionist for the Center for Science in the Public Interest, noted that symptoms of B12 deficiency include fatigue, tingling and numbness in the hands and feet, muscle weakness and loss of reflexes, which may progress to confusion, depression, memory loss and dementia as the deficiency grows more severe.

 

Folic Acid, B6, B12 Helps Prevent Stroke

As reported in the New England Journal of Medicine in 2006, the Heart Outcomes Prevention Evaluation (HOPE) 2 trial, which included 5,522 patients older than 54 years with vascular disease or diabetes, found that daily treatment with 2.5 mg folic acid, 50 mg vitamin B6, and 1 mg vitamin B12 for an average of 5 years reduced homocysteine levels and the risk of stroke.