The Essential Vitamin Every Midlife Woman Needs to Monitor

Feeling off in midlife? It could be your vitamin B12 levels

When Paige was 46 years old, she had a very sore tongue that felt like it had burned from drinking something hot.

“I also had a twitchy eyelid that just wouldn’t go away,” she said. “At the same time, I was acting quite irrationally for me (I’m a VERY rational person), so I just chalked that up to perimenopause.”

Her tongue situation got worse, so she finally went to the doctor. She tested her vitamin B12, and it was on the very low end of the normal range. Paige started B12 shots, spaced about a week apart, and then switched to a sublingual supplement.

“My tongue felt better instantly,” she said. “My eyelid stopped twitching, and I started to feel like a rational human being again.”

Her doctor tried to determine why she wasn’t absorbing B12 from the meat she was eating.

“We tested for H. Pylori, but that was negative,” Paige said. “I don’t appear to have any intestinal diseases, either. “

That was five years ago and since then, no return on symptoms. But thankfully, her doctor tested her, otherwise she might have suffered longer, assuming it was perimenopause.

This illustrates why vitamin B12 is so important to monitor from midlife on. Let’s dig a little deeper.

Vitamin B12’s function

Vitamin B12, or cobalamin, is an essential water-soluble micronutrient vital for neuronal health and red blood cell production.

Bone marrow continually makes red blood cells in a process called erythropoiesis. It starts with baby red blood cells called erythroblasts, which require vitamin B12 and folate to fully grow and develop.

Without adequate levels of B12 and folate, red blood cells enlarge, and macrocytic anemia can occur, although women won’t always reach the anemia state.

Vitamin B12 also supports the nervous system. Having optimal levels in blood and tissues helps to prevent disorders of the central nervous system, mood disorders, and vascular and Alzheimer’s dementia later in life.

Vitamin B12 is a cofactor of methionine synthase and L-methylmalonyl-CoA mutase, which is involved in the metabolism of homocysteine and methylmalonic acid metabolism.

The homocysteine connection

Homocysteine is a sulfur-containing amino acid. Lower intake and/or absorption of B12 and other B vitamins, which are cofactors in its metabolism, can raise homocysteine blood levels.

And get this: researchers have known for decades that homocysteine inches up as women go through the menopause transition. Researchers believe estrogen plays a role in the methylation process.

This is a problem because high homocysteine can damage blood vessels. According to a 2019 study, declines in estradiol as women transition through menopause led to elevations in homocysteine, contributing to endothelial dysfunction.

A 35-year study of women (average age 47) showed a link between high midlife homocysteine levels and an increased risk of dementia and Alzheimer’s disease later in life.

This emphasizes the potential importance of detecting high tHcy in middle aged women, as homocysteine lowering treatment, if shown promising in ongoing and future studies, is safe and not costly

- Zylberstein et al, Neurobiological Aging, 2011

By the way, this study was in 2011, so where are the studies following up on this? Why isn’t the menopause brain researcher Dr. Mosconi focusing on homocysteine? Just sayin…

Why and how B12 can go low

Vitamin B12 is an at-risk micronutrient at midlife because we can get enough from diet but still be deficient because of its complicated absorption.

First, we need sufficient stomach acid to cleave B12 from food, a process that can decline with age.

As people age, they are more likely to take medications like metformin and proton pump inhibitors, which interfere with vitamin B12 absorption. And anyone with inflammatory bowel disease or gastritis is at risk for poor absorption.

A much smaller percentage of people deficient in B12 have pernicious anemia which occurs more frequently in those over 60 accounting for 1-2% of all deficiencies.

In these cases, an autoimmune reaction destroys intrinsic factor (another step in its absorption), preventing B12 absorption. People with pernicious anemia need B12 injections.

Symptoms of B12 deficiency

Typical symptoms of vitamin B12 deficiency include fatigue, shortness of breath, brain fog, memory issues, depression, constipation, numbness, tingling, and poor balance.

Yet Paige experienced a burning sensation on her tongue, also known as burning mouth syndrome (BMS), which low B12 can cause due to nerve damage.

The female to male ratio of burning mouth is 7:1, making women at much higher risk. It occurs in about 3.7% of the population without a clear etiology.

It’s most likely to occur in women three years before and 12 years after menopause between the ages of 50-70. It can involve multiple sites in the mouth, but the most common spot is the tip of the tongue (71%) followed by lips (50%) and palate (46%).

Because BMS occurs more frequently in menopausal women, researchers have established a link to estrogen.

In one study with 22 patients, 12 showed improvements in symptoms with hormone therapy. But it only occurred in women with estrogen receptors in the oral mucosa.

B vitamin and iron deficiencies may relate to BMS. In one study, 20% were anemic, 16% iron deficient and 19% had high homocysteine.

In another study, researchers took 91 patients with BMS and gave the injections of vitamin B1, B6 and B12. In 75 of those patients, there was complete remission.

They didn't test their vitamin levels, but this certainly is an interesting area where micronutrients — especially B vitamins like B12—may play a role in keeping the oral mucosa healthy. We need more research to know for sure.

Midlife is a good time to monitor B12

Midlife is the ideal time to think about vitamin B12 as should vegetarians (B12 is found only in animal foods), those with GI issues, and people on certain medications.

The Institute of Medicine recommends people over 50 consume supplemental sources of vitamin B12 either through fortification or supplementation. The reason is that B12 in supplemental form can be absorbed without requiring stomach acid.

Although it’s helpful, serum vitamin B12 is an imperfect marker. It can’t tell us for sure if our tissues have what they need.

As I write about in The Midlife Woman’s Biomarker Guide, when levels are normal with symptoms (<500pg/ml) or borderline (<300pg/ml), ask for a methylmalonic acid (MMA) and homocysteine test. When these two biomarkers are high, a vitamin B12 deficiency is likely.

I also recommend regular monitoring of homocysteine, for the reasons already mentioned.

How much should we take to keep biomarkers optimal?

The RDA of vitamin B12 is 2.4mcg, but this may not be enough to keep tissue levels adequate. According to a study with healthy 18–50-year-old’s, 4-7mcg was enough to keep MMY and homocysteine optimal. The researchers conclude:

Our findings, together with those of previous studies (7, 8, 19, 20), suggest that the current RDA of 2.4 mcg vitamin B-12/d may be inadequate for optimal biomarker status.

In his review in Blood, Ralph Green hematologist, Department of Pathology and Laboratory Medicine, University of California, Davis, recommends at least 10mcg/day of daily vitamin B12 to prevent problems.

A good multivitamin with higher B12 levels, such as those found in over 50 formulations, can work well. I take this one every other day and my homocysteine (so far) has stayed at 8.

Although many B-vitamin complexes have mega-doses of B12 and it’s not toxic, some research suggests taking too much B12 may not be good either.

If you are deficient, your doctor will prescribe much higher levels, often through B12 shots. What you take to prevent vitamin B12 deficiency is different from treating it.

But for now, getting a baseline vitamin B12 and tracking your levels while making sure you get the amounts your body needs can go a long way.

Do you check your vitamin B12 regularly? Leave a comment and let me know in the comments.

Special thanks to Paige for sharing her story! This information is not meant to replace medical advice but to educate women and promote better communication with their healthcare provider.