For a supposedly well-fed—and even overfed—society, we are sadly undernourished. Especially as we age.
I’ve reported before about the epidemic of vitamin D deficiency, which becomes worse as people get older. (Simply search the archives at www.DrMicozzi.com for more.) But there’s another common nutritional deficiency that also increases with age.
Up to 38 percent of adults may have vitamin B12 deficiency, according to a 2009 review of eight clinical trials.1 And considering how the American diet has deteriorated since then, I suspect today’s numbers are substantially higher.
In fact, modern science shows that a multitude of people—of all ages—are deficient in vitamin B12… and for a variety of reasons I’ll tell you about a little later. And this deficiency can contribute to serious, even deadly, health problems.
We’ve known that vitamin B12 deficiency can lead to anemia, neuropathy, myelopathy (spinal-cord disease), and depression.
And a number of newer studies have shown that people who don’t get enough B12 are also at higher risk for a slew of very serious conditions including cardiovascular disease, bone health issues, dementia, and general cognitive decline.
Of course, you can get vitamin B12 from your diet. But here’s the truly shocking news:
Nearly one-third of people over the age of 60 can only obtain sufficient B12 from supplementation, regardless of their diet.2
Why are we deficient in vitamin B12?
It’s becoming clearer that susceptibility to B12 deficiency changes throughout the lifecycle. Developing fetuses and older adults have the highest risk of dangerously low B12 levels.
There are several reasons why people—especially those over the age of 50—don’t get enough vitamin B12, which include:
Gastrointestinal issues. Absorbing B12 from the GI tract is a highly complex process that becomes less efficient with aging.
B12 absorption involves the stomach, small intestine, and pancreas—all of which are dependent on having a healthy GI system, including the microbiome (probiotics). But even in healthy younger adults, only about half of vitamin B12 in the food they eat actually gets absorbed into the blood during digestion.3
And things can go downhill from there. All of the B vitamins are carried in the proteins in food. The stomach relies on gastric acid and the enzyme pepsin to break out these vitamins from protein. But the older we get, the less stomach acid we produce.
Atrophic gastritis, or inflammation of the stomach lining, also reduces acid secretions. And it can create excess bacteria that bind to B12 and use it for their own purposes. Atrophic gastritis is a real problem for older adults—it’s been estimated that up to 30 percent of people over age 51 have this condition.3
Antacids. The modern epidemic of taking daily antacid drugs interferes with your normal stomach acid production. So it’s no surprise that research shows these drugs are part of the problem with vitamin B12 and other nutrient deficiencies (not to mention many other health problems)—especially as we age.3 Which is why I’ve told you over the years to avoid drugs to treat indigestion.
Antacids like Pepcid, Tagamet, and Zantac may exacerbate your ability to absorb vitamin B12, but they rarely are the sole reason for deficiency.
However, proton pump inhibitors (PPIs) like Nexium, Prevacid, and Prilosec block the secretion of gastric acid and pepsin digestive enzymes. And, as we just learned, the fewer stomach acids and pepsins there are, the fewer the opportunities are for B12 to be extracted from food proteins.
It’s important to note that PPIs don’t block the absorption of vitamin B12 from dietary supplements, since the supplement isn’t bound to protein and is free to be absorbed when it enters the intestines. So if you choose to take a PPI (and, again, I recommend against it), at least you know it won’t interfere with your B12 supplements.
Metformin. This diabetes drug is specifically known to deplete vitamin B12 stores in the body. Despite all of the benefits of metformin for reducing blood sugar, increasing longevity, and lowering your risk of cancer and obesity, it’s critical to supplement with B vitamins when you take this drug.
Amazingly, irresponsible doctors still debate whether there’s a need to prescribe B vitamin supplements whenever they prescribe metformin. If only doctors were as willing to recommend dietary supplements as they are to push prescription drugs…
Vegetarian or vegan diets. Vitamin B12 is almost exclusively found in animal sources like meat, fish, poultry, eggs, and dairy. So not only do vegetarians have trouble getting adequate supplies of this vitamin (without supplementing), but they can be deficient in fat-soluble vitamins like D and E as well.
In a moment, I’ll tell you more about the food sources of vitamin B12 and whether they’re adequate even for people who aren’t vegetarians. But first, let’s look at the research linking B12 deficiency to cognitive issues, cardiovascular disease, cancer, and other health problems that increase with age.
The risk factor for heart disease, cancer, and osteoporosis your doctor WON’T check for
As you know, sadly, most of the attention for heart disease goes to the misbegotten theory of cholesterol accumulation. Yet more and more people are being prescribed cholesterol-lowering statin drugs in a futile effort to prevent deaths from heart disease. This practice has only contributed to the epidemics of dementia, diabetes, eye disease, and other health problems we are experiencing today.
But unlike cholesterol, vitamin B12 deficiency is a real risk factor for heart disease. Why? Because B12 prevents accumulation of homocysteine in tissues.
This naturally occurring amino acid has been linked to hardening of the blood vessels, which contributes to high blood pressure—one of the chief risk factors for heart attacks and stroke.
And high homocysteine levels have also been shown in studies to be a risk factor for cancer4 and reduced bone-mineral density5—which can lead to fractures and osteoporosis.
Unfortunately, most doctors are so fixated on cholesterol, they never test—or even consider—patients’ vitamin B12 levels. During your next checkup, ask your doctor for a simple blood test to determine these levels. Many doctors have differing opinions as to what constitutes vitamin B deficiency. According to my research, a level of 200 picograms per milliliter (pg/mL) or lower is deficient. Ideally, you want your B12 level to be above 500 pg/mL. (These are very small, but important levels.)
How B12 affects cognitive function and dementia
In addition to preventing and reversing the real cause of cardiovascular disease—the U.S.’s No.1 killer—vitamin B12 also plays a critical role in the growing epidemic of Alzheimer’s disease and dementia.
In fact, B12 deficiency is increasingly recognized as a contributing factor in all types of cognitive decline, from mild memory impairment to full-blown dementia.
Numerous clinical studies have shown that B vitamin deficiency, combined with elevated homocysteine levels, creates severe risk factors for cognitive impairment.
How? Well, imaging studies have shown that vascular impairments from B vitamin deficiency causes vascular impairment. In turn, this impairment leads to insufficient cerebral blood and oxygen supply. And depriving the brain of blood and oxygen are major contributing factors in the onset and progression of dementia.
In addition, high homocysteine levels from B12 deficiency may also be neurotoxic.
Why you may not be getting enough B12 from food alone
Because vitamin B12 (like all B vitamins) is water soluble, your body stores very little of it. Consequently, you need to get adequate B12 doses every day.
And you can’t really rely on symptoms to let you know if you have insufficient levels of this critical vitamin. B12 deficiency is often missed in older adults because the most common symptoms—fatigue, anemia, weakness, constipation, loss of appetite, neuropathy, cognition problems, or walking difficulties—may be attributable to other chronic health conditions.
You might think you’re getting enough B12 from food, especially if you regularly eat meat, poultry, eggs, and dairy. But, as I mentioned earlier, research shows that because of drug effects and GI issues, over 30 percent of older people can’t get sufficient vitamin B12 from their diets alone.
That’s why the Institute of Medicine recommends that people over age 50 get their vitamin B12 mainly from supplements, rather than food.6
Better to have “too much” B12 than too little
To avoid deficiency (200 pg/mL or lower), I recommend taking a daily high-quality B complex that includes 12 mcg of B12 (that’s easy to remember—12 of 12).
Of course, this is much more than the 2.4 mcg (micrograms) recommended by the government—but we all know the federal nutrition standards are woefully low.
My scientifically-backed B12 recommendation is based on the fact that everyone is different, so it’s key to make sure that each person gets an adequate amount of the nutrient. If it turns out you absorb B12 better than other people, you’ll simply excrete the excess in your urine—since the nutrient is water-soluble and the body uses only what it needs.
If you want to know if you’re getting too much or too little vitamin B, try this experiment. Skip your B complex for one day. If you typically had bright yellow urine while taking a supplement (an indicator of excess vitamin B), you’ll notice how the color goes away. And when you start vitamin B again the next day, your urine will remain colorless that day. That shows you didn’t get enough the day before, and your body is rebuilding stores.
Since vitamin B has been shown to be extremely safe, even in high doses, I firmly believe it is better to get a little “too much,” and excrete the excess harmlessly in the urine, than to never get enough.
And if you have trouble absorbing vitamin B, there’s no cause for alarm. You can correct even severe deficiencies with B12 injections—simply ask your doctor. Injections are very effective, as they bypass the GI tract and directly enter your blood stream. A typical course of treatment for deficiency includes an injection every one to two days for about two weeks, and then reduced to monthly treatments.
Why B is as crucial as D for promoting optimum health as we age
For overall health, I recommend that your B vitamin supplement contain approximate amounts of the following:
B1: Thiamine—50 mg
B2: Riboflavin—50 mg
B3: Niacin/niacinamide—50 mg
B4: Choline—50 mg
B5: Pantothenic acid—50 mg
B6: Pyridoxine—50 mg
B7: Biotin—100 mcg
B9: Folic acid/folate—400 mcg
B12: Cobalamin—12 mcg
A daily dose of vitamin B complex will ensure you have adequate stores of these crucial vitamins. In fact, the B vitamins may be second only to vitamin D for preventing and reversing virtually every modern disease, promoting health, and increasing longevity.
The epidemic of vitamin B12 deficiency, in parallel with the modern epidemics of cardiovascular disease and dementia, tells us that it should be a “no brainer” for all adults—and especially those over age 50—to supplement with a high-quality B vitamin every day.
1“Studies of biomarker responses to intervention with vitamin B-12: a systematic review of randomized controlled trials.” Am J Clin Nutr. 2009 Jun;89(6):1981S-1996S.
2Immune disorders of the gastrointestinal tract and liver. Med Clin North Am. 1985 Jul;69(4):675-704.
3“Vitamin B12 and older adults.” Curr Opin Clin Nutr Metab Care. 2010 Jan; 13(1): 24–27.
4“Serum total homocysteine increases with the rapid proliferation rate of tumor cells and decline upon cell death: a potential new tumor marker.” Clin Chim Acta. 2002;321:55–62.
5“B Vitamins, Homocysteine and Bone Health.” Nutrients. 2015 Apr; 7(4): 2176–2192.
6Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press, 1998.