Nutrients - Vitamin B12

Vitamin B12

Overview

All B vitamins are water-soluble, meaning that the body does not store them. Vitamin B12, also called cobalamin, is one of 8 B vitamins. It is important to know that all B vitamins help the body convert food (carbohydrates) into fuel (glucose), which is used to produce energy. These B vitamins, commonly referred to as B complex vitamins, also help the body use fats and protein. B complex vitamins are also used for healthy skin, hair, eyes, and liver. They help the nervous system function properly.

Vitamin B12 is an especially important vitamin for maintaining healthy nerve cells, and it helps in the production of DNA and RNA, the body's genetic material. Vitamin B12 also works closely with vitamin B9, also called folate or folic acid, to help make red blood cells and to help iron work better in the body. Folate and B12 work together to produce S-adenosylmethionine (SAMe), a compound involved in immune function and mood.

Vitamins B12, B6, and B9 work together to control blood levels of the amino acid homocysteine. High levels of homocysteine are associated with heart disease. However, researchers aren't sure whether homocysteine is a cause of heart disease or just a marker that indicates someone may have heart disease.

It' s rare for young people to be deficient in vitamin B12, but it' s not uncommon for older people to be mildly deficient. That may be because their diets are not as healthy or because they have less stomach acid, which the body needs to absorb B12. Low levels of B12 can cause a range of symptoms including fatigue, shortness of breath, diarrhea, nervousness, numbness, or tingling sensation in the fingers and toes. Severe deficiency of B12 causes nerve damage.

Others at risk for B12 deficiency include:

1. Vegans, vegetarians who also don't eat dairy or eggs -- vitamin B12 is found only in animal products

2. People with problems absorbing nutrients, due to conditions such as Crohn's disease, pancreatic disease, and people who have had weight loss surgery

3. People who are infected with Helicobacter pylori, an organism in the intestines that can cause an ulcer. H. pylori damages stomach cells that make intrinsic factor, a substance the body needs to absorb B12

4. People with an eating disorder

5. People with HIV

6. The elderly

Folic acid (vitamin B9), especially when taken in high doses, can mask the symptoms of a vitamin B12 deficiency. The danger is that without symptoms, someone with a vitamin B12 deficiency may not know it, and could run the risk of developing nerve damage. Anyone planning to take more than 800 mcg of folic acid should talk to their doctor first, to make sure they do not have a B12 deficiency.

Vitamin B12
Vitamin B12 is bound to protein in food. The activity of hydrochloric acid and gastric protease in the stomach releases vitamin B12 from its protein.  Once it is released, vitamin B12 begins to work quickly. It is important for the formation of red blood cells, neurological function, and DNA synthesis. It also supports the digestive system in keeping glucose levels stable.

A simple blood test can determine the level of B12 in the body. Adults who have a value below 170 to 250 pg/ml are considered deficient in the vitamin. An elevated blood homocysteine level or elevated methylmalconic acid level may also suggest a B12 deficiency.

Tests

Vitamin B12 and folate are ordered to detect deficiencies and to help diagnose the cause of certain anemias. One type of associated anemia is pernicious anemia, an autoimmune disease that affects the absorption of B12. This megaloblastic anemia occurs when the body produces antibodies against the gastric parietal cells or the intrinsic factor, resulting in B12 malabsorption.

Folate, B12, and an assortment of other tests may be ordered to help evaluate the general health and nutritional status of a person with signs of significant malnutrition or dietary malabsorption. This may include people with alcoholism, other liver diseases, gastric cancer, and those with malabsorption conditions such as celiac disease, tropical sprue, Crohn’s disease, inflammatory bowel disease, and cystic fibrosis.

B12 and folate may also be ordered to aid in diagnosis when an individual presents with an altered mental state or other behavioral changes, especially in the elderly. B12 may be ordered with folate, by itself, or with other screening laboratory tests (antinuclear antibody, CRP, rheumatoid factor, CBC and chemistry blood tests) to help establish reasons why a person shows symptoms of neuropathy.

In those treated for known B12 and folate deficiencies, these tests will be ordered occasionally to monitor the effectiveness of treatment. This is especially true in those who cannot properly absorb B12 and/or folate and must have lifelong treatment.

Recommended Daily Allowance

If you are considering taking a B12 supplement, ask your health care provider to help you determine the right dose for you.

Daily recommendations for dietary vitamin B12 are listed below.

Pediatric

 Newborns - 6 months: 0.4 mcg (adequate intake)

 Infants 6 months - 1 year: 0.5 mcg (adequate intake)

 Children 1 - 3 years: 0.9 mcg (RDA)

 Children 4 - 8 years: 1.2 mcg (RDA)

 Children 9 - 13 years: 1.8 mcg (RDA)

 Teens 14 - 18 years: 2.4 mcg (RDA)

Adult

 19 years and older: 2.4 mcg (RDA)*

 Pregnant women: 2.6 mcg (RDA)

 Breastfeeding women: 2.8 mcg (RDA)

*Because 10 - 30% of older people may not absorb B12 from food very well, people over 50 should meet their daily requirement through either foods fortified with vitamin B12 or a supplement containing B12.

Cautions

If the B12 deficiency is not remedied, permanent nerve damage can occur. Neuropathy is a common problem for people with diabetes, who experience pain, tingling, and numbness in their arms, hands, legs, and feet, resulting in sores.

Vitamin B12 is an especially important vitamin for maintaining healthy nerve cells, and it helps in the production of DNA and RNA, the body's genetic material. Vitamin B12 also works closely with vitamin B9, also called folate or folic acid, to help make red blood cells and to help iron work better in the body.

Food Sources

Vitamin B12 is found only in animal foods. Liver, sardines, and salmon rank highest, with liver running away with it. Kidney, eggs, beef, and pork are also good sources. There are no vegetarian sources. Supplements include - Methylcobalamin is probably the best.

Precautions

One large study found that women who took 1,000 mcg of vitamin B12 along with 2500 mcg of folic acid and 500 mg of vitamin B6 daily reduced their risk of developing AMD, an eye disease that can cause loss of vision.

Fatigue is one of the symptoms of a vitamin B12 deficiency. One preliminary study indicated that people with chronic fatigue syndrome might benefit from B12 injections, although more research is needed to know for sure.

Although there is no evidence that vitamin B12 alone reduces the risk of breast cancer, population studies have shown that women who get more folate in their diet have lower risk of breast cancer. Vitamin B12 works with folate in the body, so it may help contribute to a lesser risk. Another preliminary study suggested that postmenopausal women who had the lowest amounts of B12 in their diet had an increased risk for breast cancer.

Studies suggest that vitamin B12 supplements may improve sperm counts and sperm mobility. However, the studies were of poor quality. Better studies are needed to see whether B12 has any real effect.

Possible Interactions

If you are currently being treated with any of the following medications, you should not use vitamin B12 supplements without first talking to your health care provider.

Medications that reduce levels of B12 in the body include:

Anti-seizure medications -- including phenytoin (Dilantin), phenobarbital, primidone (Mysoline)

Chemotherapy medications -- particularly methotrexate

Colchicine -- used to treat gout

Bile acid sequestrants -- used to lower cholesterol; include colestipol (Colestid), cholestyramine (Questran), and colsevelam (Welchol)

H2 blockers -- used to reduce stomach acid; include cimetidine (Tagamet), famotidine (Pepcid AC), ranitidine (Zantac)

Metformin (Glucophage) -- medication taken for diabetes

Proton pump inhibitors -- used to reduce stomach acid; include esomeprazole (Nexium), lansprazole (Prevacid), omeprazole (Prilosec), and rabeprazole (Aciphex)

Antibiotics, Tetracycline -- Vitamin B12 should not be taken at the same time as tetracycline because it interferes with the absorption and effectiveness of this medication. Vitamin B12 should be taken at different times of the day from tetracycline. All vitamin B complex supplements act in this way and should be taken at different times from tetracycline. In addition, long-term use of antibiotics can lower vitamin B levels in the body, particularly B2, B9, B12, and vitamin H (biotin), which is considered part of the B complex vitamins.

Do You Have Happy or Unhappy Feet?

Most articles about shoes are written for women, by women, and I do not totally understand why. Is it because women own more pairs of shoes and require a pair for every dress they wear and others for when they hike, or get out in the country? Men often wear shoes that do not fit properly and then they wonder why they have sore feet and areas on their feet that are hard because of calluses that aren't taken care of until sores develop.

Why is that people with diabetes refuse to take care of their feet until forced to because of a possible amputation looming. Yes, I am being anything but understanding or sympathetic toward people who have diabetes and insist on abusing their feet. When they start complaining about feet that hurt, they know that I will not feel any sympathy and may be very difficult to get along with. Yes, I am aware of this being the wrong way to make friends and influence people. Even in the diabetes clinic, I see people wearing shoes that are wrong – spike heels, flip-flops, sandals with poor heal support and other improper shoes.

I have finally met two doctors that are very strong advocates for proper footwear. I could not believe it when I heard it, but one doctor will not treat patients for foot problems, men or women, wearing improper footwear. The type 2 patient, a man wearing flip-flops had cut his foot at home after dropping a glass container, which broke in many pieces. The doctor told him he would need to go the emergency room for treatment. The ER doctor did treat him, but said he would need to purchase a proper set of house slippers or shoes to continue being treated if he had problems healing.

Both doctors are very set on people with diabetes wearing proper footwear. The doctor that has his own practice does have a foot measuring device to show people the correct size and posters showing the incorrect footwear for both men and women. If you don't want to be embarrassed when he insists on measuring your foot and tells you your shoes are too small, you will want to avoid this doctor. His advice is correct though as many people insist on wearing shoes that are too small for them. A few people do wear shoes that are too large. This is an invitation for developing blisters and calluses.

This article from WebMD has some excellent pointers and even if the United Kingdom is the setting, the information is still valid. The information given shows that only 25 to 40 percent of people with diabetes wear shoes that are the correct size. Because the information given is great, I will quote it. “When people with diabetes start experiencing nerve damage or numbness, they often gravitate toward shoes that are too small because tight shoes make it easier for them to feel the snugness on their feet. They mistake that tightness for good support. Instead, they need to wear shoes with comfortable -- not tight – support.”

“Once you know your correct size, here are nine guidelines for choosing shoes when you have diabetes:

1. Look for shoes that don't come to a point at the toe. Instead, choose shoes with a spacious "toe box" -- the forward tip of the shoe where the toes are. That way your toes won't be crushed together. When your toes have space, it lessens the chance of corns, calluses, and blisters that can turn into ulcers and eventually infections.

2. If the shoe's insole is removable, take it out and step on it. Your foot should fit comfortably on top of it with no overlap. If your foot is bigger than the insole, then your foot will be crammed inside the shoe when you wear it. Choose a different shoe.

3. Avoid high-heeled shoes because they put unnatural pressure on the ball of your foot. If you have neuropathy, you may not realize that you are sore there or even getting calluses. High heels also can cause balance issues and ligament damage.

4. Steer clear of sandals, flip flops, or other open-toe shoes. Straps can put pressure on parts of your foot, leading to sores and blisters. In addition, open shoes can leave you susceptible to injury like cuts. They also can allow gravel and small stones to get inside the shoe. These can rub against your feet, causing sores and blisters.

5. Consider laced shoes instead of slip-ons. They often provide better support and a better fit.

6. Try on shoes at the end of the day. That's when your feet are more likely to be a little swollen. If shoes are comfortable when your feet are swollen, they should feel fine the rest of the time, too.

7. Don't buy shoes if they are uncomfortable, planning to break them in as you wear them. Shoes should feel good when you first try them on. If you take off new shoes after wearing them a couple hours and find red, sensitive spots, don't wear them again.

8. Buy at least two pairs of supportive, comfortable shoes. Each pair will likely have different pressure points on your feet, so it will relieve the pressure when you alternate wearing different shoes. It will also allow your shoes to dry and air out when you don't wear them every day.

9. In some cases, the cost of special shoes is covered by Medicare for people with diabetes. You must meet certain criteria -- such as foot deformities, past foot ulcers, or calluses that can lead to nerve damage -- and must have a doctor's prescription. Talk to your podiatrist or primary care doctor for more information.”

The above is a reason everyone with diabetes should see a podiatrist at least yearly, if not quarterly to have their feet examined and problems found early and corrected.

If you find shoes that fit correctly, wear them at all times – except when sleeping. Do not go barefoot, even around your own house. This is where most problems start for people that have neuropathy or other foot numbness, as they don't feel anything when they step on something sharp and injure themselves. Then the area becomes infected and problems start.

Now one final word of advice, before you opt for the overly uncomfortable shoes on special occasions, talk with a podiatrist first. Let the podiatrist tell you if these shoes can be worn for short periods of time like that special party. If the podiatrist advises against this, do follow the directions as it is your feet and you don't want to see the doctor later to correct the damage you could have prevented.

Joslin Advocates for SMBG

This is an interesting turn of events. Normally I am the one complaining about the lack of self-monitoring of blood glucose, but now Joslin Diabetes Center is asking in their book Joslin's Diabetes Deskbook, 2nd Ed, Excerpt #4: Do Your Patients Self-Monitor Their Blood Glucose Enough? For this, I have to ask if they will appeal to the Centers for Medicare and Medicaid Services (CMS) to up the number of test strips that diabetes patients can be reimbursed.

I complain because people do not test enough and use the results to help manage their diabetes in as more informed manner. I appreciate Joslin's statement, “It is imperative that people who are self-monitoring know what to do with the results of their glucose checking so that they can take active steps to improve their control. They should be given instructions on how to interpret their results, what they can do themselves in response to the results, and when they should call for help.” At least the authors know and understand the importance of education and that it should be part of every diabetes treatment plan.

Too many doctors do not even prescribe a meter and test strips for patients on oral medications, meaning patients with type 2 diabetes. This excerpt should be required reading for these self-important doctors. All doctors do either give out meters and prescribe test strips or inform their patients where to obtain testing supplies for people with type 1 diabetes and for people with type 2 diabetes on insulin.

I like what is covered in chapter 3. They state that, “Goals of diabetes treatment need to be defined in terms of self-monitoring results.” This is a great statement, which patients with diabetes need to understand. This brings both patients and physicians into the picture and makes each a participant. The patients are responsible for gathering the information, doing this diligently, and providing this information to the physicians. Then the physicians are responsible for taking this information and helping the patients set goals (whether new or revised) to help then manage their diabetes more effectively.

In summary, here are a few reasons why SMBG should be performed:

1. To provide data about glucose patterns that can be used by the healthcare team, working with the patient, to make treatment manageable.

2. To provide data with which patients themselves can make daily decisions on treatment adjustments.

3. To provide feedback on how effectively the individual is managing daily self-care routines, including medical nutrition therapy, physical activity, and medication use.

These are by no means the only reasons and the tables uses are adapted from the American Diabetes Association and are therefore not ideal, but can only be interpreted as suggestive for patients that are elderly or have other diseases, which affect their ability to manage their diabetes more effectively. Those patients that are younger and fully able to manage their diabetes need to consider using these tables.

Another area of concern is a few of the “diabetes coaches” that tell their people not to give the information to their doctors. Granted some doctors do not know what to do with the information, but they are on their way out of practice as patients become more empowered. I have crossed paths with a few of these “coaches” and know they are attempting to hide what they are doing. Not that they are giving out advice that is out of line, but too often these “coaches” are practicing medicine without a license. They may not have intended to, but they do cross the line time after time.

Happy Holidays!

Happy Holidays

Wishing you and your family a Merry Christmas and a Happy New Year!

Note: No blog will be posted on 25 December 2012