Taking care of loved ones, tackling work tasks, tending to errands and household chores … We do so much on a daily basis that we all battle fatigue and brain fog from time to time. But if you’re losing the battle day after day, you could be suffering from a deficiency in vitamin B12. The vitamin is crucial for generating energy. And as Angela DeGrassi, 48, can attest, there’s a surprising link between the drug metformin and B-12 that makes draining deficits more likely. Keep reading to find out more about this common problem and how to know if you might have it. Then learn how Angela quickly reversed her B-12 deficiency —and how you can, too!
Why vitamin B-12 is so important
Also known as cobalamin, B-12 is an essential nutrient for the body. "B-12 plays a vital role in metabolizing fat, protein and carbs into energy,” explains Fred Pescatore, MD. Plus, it’s crucial for making healthy red blood cells that transport energizing oxygen through the body and protecting the myelin sheath that surrounds nerves. So when the body runs short on B-12, women experience symptoms such as fatigue, blue moods and brain fog. But doctors don’t always associate these symptoms with B-12 deficiency. In fact, researchers in the journal Age and Ageing found 78% of people who suffered from B12 shortfalls were undiagnosed.
Why B-12 deficiency is on the rise
Deficits in vitamin B-12 are 733% more common than doctors previously thought, according to findings from an NIH study. Research in the journal Heart and Circulatory Physiology reveals a mutation in a gene known as MTHFR C677T can increase the risk of B-12 deficiency by 320%. But even women who don’t harbor the genetic variation can experience shortfalls due to other common factors:
1. Low stomach acid blunts B-12 absorption
The body needs gastric acid to separate B-12 from proteins it's bound to so the body can properly absorb the vitamin. But according to Michelle Schoffro Cook, PhD, drop-offs in stomach acid impact up to 80% of women 50 or older. And in a study published in the journal Nutrients, prevalence of B-12 deficiency increased by 77% after age 50.
2. Metformin and heartburn medications lower B-12 levels
The medication metformin treats diabetes, prediabetes and polycystic ovarian syndrome (PCOS). Plus, some doctors prescribe it for weight loss and longevity. But metformin impedes absorption of B-12 in the small intestine. And a recent study in the journal Endocrine Practice determined taking metformin for 4 years or more increased the risk of B-12 deficiency by 41%. What’s more, investigators in The International Journal of Basic & Clinical Pharmacology found people who took metformin experienced significant B-12 dips in as little as three months.
Drugs that ease heartburn by suppressing stomach acid are also offenders, say experts reporting in JAMA. They found that taking proton pump inhibitors (PPIs) for 2 years increased B12 deficiency risk by 68%. And taking histamine 2 receptor antagonists for two years raised the risk by 25%.
3. Plant-based diets can lack B-12
Vitamin B-12 abounds in animal meats, eggs and dairy foods. But most fruits and vegetables contain trace amounts of B-12 at best. That’s the reason a European Journal of Clinical Nutrition study found vegetarians were a whopping 1,844% more likely to be deficient in B-12 than their omnivorous counterparts.
Is a B-12 deficiency triggering your tiredness?
Doctors use blood tests to diagnose B-12 deficiency, but those that measure B-12 alone can produce false results. And as Dr. Pescatore points out, levels that many doctors consider normal can lead to draining symptoms. His advice: Ask your doctor for additional tests that measure homocysteine and MMA (methylmalonic acid). Levels of these substances climb in the blood when B-12 is in short supply. Red-flag symptoms can also yield valuable clues. So if you experience the following, a B-12 shortage could be to blame:
Numbness or tingling in hands or feet
Easy ways to optimize B-12 levels
Doctors can reverse B-12 deficiency with intramuscluar injections of the vitamin. But the shots can be offputting if you’re one of the 63% of folks who fear needles. Plus, B-12 insurance doesn't always cover the injections. Fortunately, the following strategies can outsmart B12 shortfalls to restore energy, upbeat mood and more.
1. Take a daily B-12 supplement
B-12 supplements are as effective as intramuscular injections, according to British researchers. And taking them can lift energy in as little as four weeks, according to Dr. Pescatore. He advises taking 2,000 mcg of methylcobalamin (a form that’s readily used by the body) daily and opting for a sublingual supplement. Doing so compensates for shortages in stomach acid by delivering the vitamin via blood vessels under the tongue. To try: Solgar, Sublingual Methylcobalamin (Vitamin B-12), 1,000 mcg (Buy at Amazon, $18.70 for 60 nuggets). Also smart: Take 1,000 mcg of methylfolate daily since the B vitamin works in tandem with B-12 to boost energy.
2. Make easy diet tweaks
Processed foods typically contain less than half the B-12 than natural foods, say Brazilian experts. In fact, their study suggests cutting back on processed fare lifts body levels of B-12 by 32%. Dr. Pescatore also recommends limiting sugar and alcohol as much as possible (both can deplete B-12) and enjoying foods high in B-12 such as beef, poultry, eggs, tuna, sardines and salmon twice daily.
In addition, he advises incorporating folate-rich foods such as broccoli, Brussel sprouts, beans and sunflower seeds into daily menus. And to decrease pH levels in the stomach and boost B-12 absorption, Ann Louise Gittleman, PhD, suggests drinking 2 teaspoons of apple cider vinegar in 8 ounces of water before every meal.
3. Check your B-12 levels often if you’re taking metformin
Drug-induced vitamin B-12 shortfalls often go undetected: In a study published in the Journal of the Endocrine Society, only 7.6% of primary care physicians monitored B-12 levels in patients who were on metformin. If you’re taking metformin for any reason, Dr. Pescatore recommends getting the blood tests mentioned above to check for B-12 deficits every 6 months.
Metformin and B-12 success story: Angela Grassi, 48
For Angela Grassi, every day was a battle against fatigue. Then she uncovered the shockingly common culprit and a fast-acting fix. Here's her story:
"Do you mind if we order takeout … again?” Angela asked her family, trying to mask the guilt and frustration she felt that fatigue, once again, meant she was too tired to make dinner. “I’d been so tired that it was hard to summon the energy to function through brain fog and tiredness,” she recalls, “so I ordered their dinner and dragged myself to bed, hours earlier than normal, feeling guilty for letting my family down again.”
Angela couldn't push past the fatigue
“My health struggles began when I woke up feeling exhausted every morning despite getting a good night’s sleep. I’d get up and feel like I needed to go back to bed. But devotion to my family pushed me to power through my day as a working mom and wife. Typically, the exhaustion caught up with me, and by late afternoon, I was absolutely wiped out and in desperate need of collapsing on the couch well before dinner.
“Guilt and anger consumed me because I wasn’t as present for my family as I wanted. At first, I excused away my fatigue, thinking it was the result of everyday life and being busy or simply getting older. But as weeks of exhaustion turned into months, there was a new health twist: I started experiencing unexplained moodiness, then tingling in my hands. That’s when my gut told me it was time to start digging into my health issues.
How Angela discovered the cause of her symptoms
“Because I’m a registered dietitian, I know how to eat properly, and I was doing that, making sure my diet consisted of fruits and vegetables to ensure nutrition. So I decided to start researching sneaky culprits that can zap energy. That’s when I came across research that showed that the prescription medication metformin can affect vitamin B-12 levels in as little as three months of use, and that decreased vitamin B-12 levels are a known consequence of long-term treatment with metformin.
“I had been on the medicine for close to 20 years to treat my polycystic ovary syndrome (PCOS). Although the exact reason isn’t understood, it’s believed that metformin interferes with the body’s ability to absorb vitamin B-12, leading to a deficiency. No wonder I’m always so tired! I thought, as I began to hope and wonder if an end to my constant fatigue was finally possible. I also read the book Could It Be B12? An Epidemic of Misdiagnoses, and that was really eye-opening because the authors suggest that the ideal reference range to diagnose B-12 deficiency is set too low.
The metformin and B12 connection
“Wondering if the medicine I relied on to help keep me healthy might also be making me feel so worn out, I scheduled an appointment with my doctor, who performed a blood test to check my B-12 levels. The results indicated I was severely deficient in B-12. My doctor explained that ceasing taking the metformin wasn’t an option since I needed it to keep my PCOS controlled.
"He recommended I begin supplementing with a sublingual form of vitamin B-12 called methylcobalamin, the active form of the vitamin. He explained that I should put the tablet under my tongue for best absorption instead of swallowing it like other supplements. He recommended taking 500 mg. twice a day after breakfast and dinner. He explained that this specific type of vitamin B-12, which I bought online, is best used to treat deficiencies because it is a naturally occurring form of the nutrient, and that made it better for overcoming my deficiency.
How Angela restored her energy
“I immediately started taking B-12 at the dose he recommended, and within a few short weeks, I began to notice that my energy levels started to soar. Instead of wishing I could fall back into bed every morning or struggling to stay awake past 6 pm, I started looking forward to making dinner with my family or reading or watching a movie well past 9 pm.
“Thanks to regular vitamin B-12 supplementation, I am thrilled to report that I now have a ton of energy to charge headfirst into my day. I no longer find myself wishing I could take a midmorning nap or needing to turn in early!”
A version of this article originally appeared in our print magazine, First For Women.
This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.
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