Posted
Thursday, May 20, 2010
I’ve been warning for years about the danger of metformin, the most commonly prescribed drug for diabetes, and the need to monitor homocysteine levels and B12 status. Now, a trial, published the British Medical Journal today, which gave 850 mg of metformin to 196 of the study’s participants and a placebo to the other 194 people three times daily for more than four years, confirms this.
People who had taken the metformin were found to have a 19% reduction in their vitamin B-12 levels, compared with people who had taken a placebo, who had almost no change in their levels during the study. In addition, the reduction of levels of vitamin B-12 by metformin was not temporary, but persisted and became more apparent over time.
There was also a significant rise in the number of people with deficient levels of vitamin B-12 over the period of the study if they had been taking metformin, from three patients to 19. The equivalent number for the placebo group rose from four patients to five. Compared with people taking a placebo, people taking metformin also had a 5% increase in homocysteine, but their folate levels were the same. Homocysteine levels increased especially in individuals in whom vitamin B-12 levels decreased - showing that the decrease in vitamin B-12 levels were functionally meaningful. The authors say: “Our study shows that it is reasonable to assume harm will eventually occur in some patients with metformin-induced low vitamin B12 levels.” Raised homocysteine is associated with increased risk for strokes, cardiovascular disease, osteoporosis, depression and age-related memory loss.
Current guidelines indicate that metformin is a cornerstone in the treatment of type 2 diabetes, but make no recommendations on the detection and prevention of vitamin B-12 deficiency during treatment, they add. “Our data provide a strong case for routine assessment of vitamin B-12 levels during long term treatment with metformin.”
My recommendation is to use chromium instead of metformin. At doses of 600mcg a day (most supplements provide 200mcg, so that means three a day) chromium is more effective than metformin at stabilising blood sugar levels. A systematic review in the top journal Diabetes care says ““Among participants with type 2 diabetes, chromium supplementation improved glycosylated hemoglobin levels and fasting glucose. Chromium supplementation significantly improved glycemia among patients with diabetes.” Cinnamon also has benefits and supplements combining high dose chromium with cinnulin, a specific extract of cinnamon, are my favourite.
If you are on metformin do check your homocysteine level. If raised you need to supplement more B12. The RDA is far too low. A basic level to supplement for everybody is 10mcg a day. A good multivitamin needs to provide this. But if you are low, or your homocysteine level is high, you’ll need more like 500mcg to correct deficiency. B12 is increasingly poorly absorbed as you age and is only found in animal products.
I am not diabetic, and not on any drugs, but am vegetarian. What’s the best way of getting enough B12 in the diet, and how much is it wise to supplement? Thanks.
Posted by jilly.richardson@hotmail.co.uk on 06/01 at 10:25 AM
B12 is in milk and eggs but it is not easy to get enough as a vegetarian. Although algae is claimed to contain B12 it is not ‘functional’ B12 and really doesn’t count. The RDA is too low at 1 or 2mcg. I recommend everyone achieve 10mcg, which is the kind of level to look for in a daily multivitamin.
If your homocysteine level is raised this is a pretty good indicator that you aren’t getting enough. This is often due to poor absorption, which becomes increasingly common with age. If your b12 level is actually low you may need a lot more orally to correct deficiency aka 500mcg a day. Methylcobalamine is the best form for oral absorption if your status is low.
My online 100% Health Programme includes a good symptom check for B12 status.
Posted by patrick on 06/01 at 12:01 PM
I was diagnosed with type 2 diabetes in March 2010 & am currently taking 500mg metformin twice daily. Is your advice to talk to my GP and stop taking the metformin & increase chromium from the 400mcgs I take currently to 600mcgs. I also have raised cholesterol and am under pressure from my Gp to take statins which so far I have resisted doing. I am trying to reduce it myself by following your diet & will be having another blood test this coming week
Thankyou
Christine
Posted by christine21mason@hotmail.co.uk on 06/13 at 01:40 PM
Many diabetes specialists recommend reducing metfromin dose to one a day once your blood sugar is stable, for at least a week, below 6, ideally averaging 5.5. Then, if you achieving the same goal on 1 metformin 500mg they often recommend that you stop. By strictly following my low GL diet, and taking 400mcg of chromium am, and 200mcg pm, and als exercising every day, you have the best chance of achieving this goal quickly. My advice is to stay on the medication you are taking, but do all the rest and whn your blood sugar becomes stable then talk to your doctor about a trial period on less medication if that is your wish.
Also, the most important measure of blood sugar control is your glycosylated haemoglobin (HbA1c). If you can get this below 6 with changes in diet and supplementation that gives your doctor even more confidence to stop medication.
Meanwhile it is important to monitor your homocysteine and, at least, take a multivitamin containing B12 10mcg. Ideally test your homocysteine level first.
Regarding statins niacin is more effective and also prescribable as Niaspan. Your doctor is remunerated by lowering your cholesterol by whatever means. The list of side-effects for statins just keeps growing. You are right to be cautious. It is highly likely that your cholesterol will come down with the same strategy for controlling your blood sugar levels. Your goal is to have at least one third of your cholesterol as HDL for example, 5 units of total cholesterol and 1.7 untis of HDL.
Posted by patrick on 06/14 at 08:28 AM
patrick keep up your good work!
we all need health experts like yourself,
you really have opened our eyes when it comes to nutrition.
Posted by aisha on 06/29 at 12:23 PM
Following my earlier comment, I recently had the second blood test for cholesteroland this showed that my levels had dropped quite significantly. Total cholesterol down to 5.8 from 7.6. HDL up to 1.25 from 1.13. Ratio down to 4.6 from 6.7. LDL now at 3.8 (no previous number recorded). All this without medication, just your Low GL Diet and recommended supliments. on this visit to my GP no mention was made of statins being needed. I know that further improvement needs to be made but thankyou so much for the advice you gave in your reply. Also my HbA1c is at present 7.4 which I know also needs to improve but, again, overall my daily blood glucose levels are improving so hopefully this will continue with your diet. It’s the daily exercise I have trouble with. Once again thankyou so much for your help & advice and the monitoring of health issues that you inform us about on this website.
Thankyou
Christine
Posted by christine21mason@hotmail.co.uk on 07/04 at 10:42 AM
HbA1c is a ‘long-term’ measure and takes a couple of months to really come down, so keep going. Even 30 minutes brisk walking, perhaps 15 mins to the shops and back, is worth doing. Well done.
Posted by patrick on 07/05 at 05:57 AM
Following on from Christine’s comments regarding statins and niacin, I recently re-read your Special Report on ‘What to do if you have high cholesterol’ (SP19-10/07). This gives recommendations for various supplements to raise HDL/lower LDL including CoQ10, and Omega 3 fish oil. I was about to order BioCardio for my mother-in-law from the Total Health website, but noticed the warning ‘Not suitable for individuals taking anti-blood clotting medication such as Warfarin, Coumarin or Heparin’. I think she IS taking anti-clotting medication, so now I’m not sure what to do - I’m not qualified to advise her. Any advice would be welcome. Thank you.
Posted by jilly.richardson@hotmail.co.uk on 07/07 at 10:17 PM
I’m sure the concern, which is mild, is that omega 3s also help to thin the blood. It is all a question of doses and degrees. If you have Food is Better Medicine Than Drugs it talks about this, and increasing natural blood thinners, while reducing medication so as to maintain a stable INR. This requires their doctor’s cooperation
Posted by patrick on 09/07 at 04:18 PM
