Metformin and Risk For Vitamin B12 Deficiency

[janal]

I came across this article tonight while searching for something else. I thought it was an interesting article and thought I'd post it for other diabetics to see.

Hope it is helpful.

http://www.diabetesselfmanagement.co...12_deficiency/

Metformin and Risk For Vitamin B12 Deficiency
Amy Campbell
Metformin (brand names Glucophage, Glucophage XR, Fortamet, Riomet, Glumetza, and others) is a popular and highly effective oral diabetes drug used to help manage Type 2 diabetes. This drug works by lowering the amount of glucose made by the liver and by making the body’s cells more sensitive to insulin. Metformin also has some other beneficial effects in that it may help lower blood lipid, or fat, levels (cholesterol and triglycerides) and can, in some people, promote a small amount of weight loss.
Metformin can be used with other diabetes pills and with insulin. Side effects of taking metformin are relatively rare, the most common being bloating, nausea, and diarrhea, all of which are temporary. Some people shouldn’t take metformin, including people with kidney disease, liver disease, or congestive heart failure, for example, because of an increased risk of a potentially fatal condition called lactic acidosis.
In recent years, there’s been some concern over the risk of vitamin B12 deficiency in people who take metformin. Vitamin B12 (also known as cyanocobalamin or cobalamin) plays many important roles in the body, such as keeping your blood cells and nervous system in tip top shape. There’s also some evidence that vitamin B12 may help prevent heart disease and possibly even Alzheimer disease (the jury is still out on this one). This vitamin is found primarily in animal foods, such as beef, seafood, eggs, and dairy products, which is why some vegetarians are at risk for a B12 deficiency. Elderly people are often at risk for deficiency as well, due to problems with absorption from the gastrointestinal tract. Symptoms of B12 deficiency include certain types of anemia, neuropathy, memory loss, confusion, and even dementia.
So, why would taking metformin possibly put you at risk for a B12 deficiency? According to some studies, between 10% and 30% of people who take metformin on a regular basis have some evidence of decreased B12 absorption. Researchers aren’t quite sure why this happens. In a study recently published in the October 9 issue of the journal Archives of Internal Medicine,155 Chinese people with Type 2 diabetes taking metformin were identified as having a B12 deficiency, regardless of factors such as age or body weight. The study found that the longer a person had been taking metformin and the higher his daily dose of the drug, the greater his risk of developing B12 deficiency.
The authors of the study advocate consideration of vitamin B12 deficiency screening for people who take metformin. While this screening isn’t routine, it’s worth it to have a talk with your health-care provider to see if you’re at risk for deficiency, especially if you’ve been taking metformin for several years or take a high dose. Also, if you have any of the symptoms of B12 deficiency mentioned above, particularly those related to neuropathy (numbness, pain, or tingling in your hands or feet), be sure to let your physician know. He or she can check the level of vitamin B12 in your blood.
Vitamin B12 deficiency can be treated with either oral, injected, or inhaled forms of B12. Some people, such as strict vegetarians or the elderly, may need to take supplements or receive injections on a regular basis. B12 is found in most multivitamin supplements, so it doesn’t hurt to take a multivitamin as a safeguard. However, avoid taking a B12 supplement unless your doctor has prescribed them. Too much vitamin B12 may be harmful, and B12 can also interact with certain medicines. Always let your health-care team know about all medicines and supplements that you’re taking at each visit.

1. I am 72 years old and am a type 2 diabetic. For 5 years I have been taking Metformin 500 x 3 times per day. Tingling/numbness in my feet, pains in legs and ankles also swelling (possible odema) weight gain and general tiredness when walking and I have made an appointment with my GP to discuss these problems re possibility of a B12 deficiency. Apart from my age, would you agree these symptoms could be linked to this type of deficiency? Any comments would be so appreciated. Thank You.
Posted by Jillybean | Aug 29, 2008 at 3:48 pm

2. Hi Jillybean,
Please realize that I’m not a physician and cannot diagnose anyone. However, some of your symptoms could be consistent with a B12 deficiency, including the tingling and numbness in your legs, and your fatigue. Weight gain and swelling are usually not linked with a B12 deficiency. I’m glad to hear that you’re going to discuss your symptoms and possible causes with your physician.
Posted by acampbell | Aug 31, 2008 at 5:33 pm

1. Thank you so much for this post. I have been taking Metformin 2000 mg per day for 8 years now for type 2 diabetes. I had lots of tingling and pain in my feet that was diagnosed as neuropathy. I got tested recently for B12 deficiency and started getting B12 shots. What a wonderful difference. The constant pain in my feet has stopped and I have more energy. The plan is to continue to get the injections and test again to make sure the B12 in my body is increasing.
Posted by Deb | Jun 29, 2009 at 1:42 pm

1. hi - i just wanted to share my experience and knowledge regarding b12 deficiencies.
pernicious anemia in and of itself is not the same as a b12 deficiency, although a b12 deficiency is a symptom of pernicious anemia and is often the determining factor for the diagnosis of pernicious anemia. while the differences are subtle, a b12 deficiency alone has less to do with blood (anemia) than with the body’s inability to absorb the vitamin from the GI tract. (for example, the CBC test would actually come back as normal, but the b12 would test low - b12 deficiency. if the CBC came back abnormal AND there was a b12 deficiency, then that points to pernicious anemia because it is blood related.) it hardly makes a difference, really, but it is interesting to know exactly why one has a b12 deficiency - malabsorption or anemia. the treatment would be the same - most likely b12 injections.
i have been on metformin 500mg 2x/daily for over 4 years to treat PCOS. i am not trying to get pregnant, but the other conditions that PCOS can cause (facial hair, insulin resistance, Syndrome X) are be helped with this medication.
two years ago, after a surge of migraines and fibromyalgia-seeming symptoms, i was diagnosed as having a severe b12 deficiency - which my doctor and i both feel were the culprit of the increased migraines and nerve pain. my doctor did not make the connection with the metformin use at first (apparently it is a rather new discovery/link), but after discussion he advised that the small dose i am taking would probably not be the cause. in the end, we decided together that i get a great deal of benefit from metformin, and the b12 injections are not too much of hardship, so i am staying on metformin and now having one b12 shot a month (in the beginning it was one every week, then as the level in my body began to rise and sustain, the frequency has been decreased). to date, my body has not yet been able to retain a sufficient level of b12, thus the continued injections.
also, while taking a b12 supplement is a good idea, remember that if malabsorption is the problem, an oral tablet of b12 will not be absorbed by the body anyway - a sublingual tablet has more of a chance since it is not absorbed through the GI tract, but passes into the bloodstream under the tongue. injections put the b12 right into bloodstream so it is immediately available to the body. additionally, the dosing available in an injection is considerably higher than what an OTC vitamin supplement can provide, so it may be necessary to maintain injections to get the b12 level up, then try to supplement with a pill.
i am not a doctor, but i am a healthcare professional. this post is to be taken as discussion only and not any medical diagnosis or advice. talk to your doctor if you have concerns about your b12 deficiency, pernicious anemia and/or your concerns about metformin use.
thanks!
Posted by Kim | Sep 08, 2009 at 5:44 pm

1. I’ve been diagnosed as a type 2 diabetic 8-18-09. I just turned 40yrs old in August..
I started on 500mg’s of metformin and my level was at 353 and came down to the 200’s in 3 weeks. My doctor says I’m not down far enough. So they upped my dosage to 2 times a day and then 3 times a day. I was wondering about this aching and pains in my legs and abdominal area. I also have the tingling in my fingers and numb big toes.. I’m glad I read this postings cause now I think I see why. I went out and purchased b-12 (1000mgs)yesterday and started … hopefully it makes me feel better and kills these aches and numbness. My level is at 125 now since the 3X a day metformin. I really have trouble sleeping because of the uncomfortable aches and pains.. I take many hot baths to soothe the pain and then it comes right back,, temporary relief is better than nothing …whew.. Hopefully the b-12 helps out. I’ve only taken one dose. Maybe in a couple days-weeks.. I’ll be back with a feel better story of my own.. wish me luck
Posted by Jay | Sep 21, 2009 at 4:10 pm

2. Hi Jay,
At the American Diabetes Association Scientific Sessions this past June, researchers presented a study that looked at vitamin B12 deficiency in people with Type 2 diabetes who were taking metformin for at least one year. They found that more than 75% of the metformin users who had low B12 levels also had peripheral neuropathy. There’s not enough evidene from this study to conclude that the low B12 levels caused or contributed to the neuropathy, but it does reinforce the need for people who take metformin to have their vitamin B12 levels checked. I do hope you’ve told your doctor about your pain and the fact that you’re taking a B12 supplement. Pain is always a cause for concern and you should let your doctor know to rule out other possible causes. And, if you truly are deficient in vitamin B12, your doctor can recommend the appropriate B12 dose for you (I assume you’re taking 1000 micrograms [mcg], not milligrams [mg]).
Posted by acampbell | Sep 22, 2009 at 8:32 am

[ScrappyKat]

"Metformin and Risk For Vitamin B12 Deficiency
Amy Campbell
Side effects of taking metformin are relatively rare, the most common being bloating, nausea, and diarrhea, all of which are temporary. "


Ha! Its not always temporary, I'm telling ya from personal experience.

[janal]

Poor ScrappyKat, not nice to have had this side effect.
I was lucky - never had any side effect like that and I'm not on the medication anymore but I do have Low B12.
Interesting!

[clearviews]

This is really exciting news (not) as I was referred to the endo with concerns about my fairly serious neuropathy. I have been in the past seriously anemic and I was very honest with him about my excessive drinking history-depletes Vit B.
He put me on Metformin. Fortunately something her said as I left "no carbs" made me find the low carb diet and after 5 months I took myself off Metformin as my BGLs were getting lower and lower.
I have been taking ALA, EPO and recently a vit B complex that is formulated for neuropathy. I am 12 months into the vitamin & mineral supplements but wonder if the Metformin set me back on my road to recovering the feeling in my feet?! I DO believe that I have regained some feeling but it is a slow process. Alcohol has a lot to answer for.

[mars]

I dont have diabetes but i have very high insulin levels , my doctor recently put me on metformin. He also just discovered that I have a genetic defect where my body doesn't absorb B12, as does my mum. So now im on Metformin, Folinic Acid and B12. I feel so much better after taking the Folinic acid! I used to feel like curling up and going to sleep in the middle of the day but now im great

[adrianab]

I had been taking Metformin for 10 years and was diagnosed by my local gp as having Vit B12 deficiency and a genetic defect that stopped me from processing Vit B12 properly. My endocrinologist whom I saw afterwards said that having the deficiency meant that I should stop taking Metformin and go onto insulin.

He said that folic acid, vitamin B6 and Vitamin B12 supplementation were contraindicated for diabetics as it worsens kidney function as well as makes neuropathy worse. He also questioned the validity of the genetic defect hypothesis. As I have both neuropathy and nephropathy - just diagnosed, he said not to take any of these vitamins. There is an article in the JAMA just recently published that he gave to me.

[Sherrie]

Hey Adrianab, I saw articles recently on B vitamins and neuropathy in Diabetes. Do you follow low carb?

[adrianab]

I follow Dr Bernsteins guidelines for managing my diet - that's about 6gm of CHO for brekkie, and 12 gm for lunch and dinner. I have been doing this since November and have seen my HbA1c fall from 7.9% in October to 5.3%.

At first I didn't think it would be doable, but seeing the results keep spurring me on. I have lost 19kg of weight as well and have much better post-prandial results doing the program.

I keep my diet pretty simple - meat and salad or vegies.

[Sherrie]

Great results there

[janal]

Excellent results there adrianab