Vitamin B12 Recommendations

Vitamin B12 Recommendations on a Plant-Based Diet

A plant-based diet has been shown time and time again to be the most health-promoting, disease-fighting, and nutrient-dense way of eating possible. Emphasizing a wide range of vegetables (especially leafy green varieties), fruits, whole grains, legumes, nuts, seeds, herbs, and spices makes it simple to achieve nutrient needs while avoiding chronic overnutrition. Guides such as the Plant-Based Food Guide Pyramid and Plate, 6 Daily 3’s, and Notable Nutrient Chart help with the high level view of what exactly a day-in-the-plant-based-life may look like. As does this post of Everything You Need to Know About A Plant-Based Diet in Less Than 500 Words and Sample Meal Plans Made Simple + Hundreds of Recipes.

One nutrient that likely will fall short on a plant-based diet is cobalamin, commonly referred to as vitamin B12. B12 is produced by microorganisms, bacteria, fungi, and algae, but not by animals or plants. B12 is found in animal products because they concentrate the nutrient after ingesting these microorganisms along with their food in their flesh, organs, and byproducts (e.g. eggs and dairy). Also, ruminant animals (such as cows, sheep, and goats) have bacteria in their rumen that produce vitamin B12.

In a vegan diet, vitamin B12 may be found in fortified plant milks, cereals, and other foods, such as nutritional yeast. However, if vegans are not conscientious about taking in the recommended dietary allowance (RDA), there could be harmful health consequences. Deficiency can result in potentially irreversible neurological disorders, gastrointestinal problems, and megaloblastic anemia. B12 deficiency is not unique to vegans who do not supplement. Deficiency is also a concern with aging, medication use, and gastrointestinal issues. So much so that it has been recommended that all adults over the age of 60 years supplement to avoid deficiency.

Interestingly, the body is able to store B12 for upwards of even ten years. To further complicate this, signs and symptoms for deficiency are either not noticeable or simply very subtle. So, if B12 is not being taken in at adequate levels or if there are absorption problems, deficiency will eventually ensue. Because blood tests for B12 levels can be skewed by other variables, irreversible damage may occur before a deficiency is detected.

RDA’s for vitamin B12 across the lifespan can be found in detail here. For non-pregnant adults, aged 14 and above, the RDA is 2.4 micrograms per day. To ensure this is absorbed (in a healthy individual, barring any possible inhibitors), higher doses are recommended.

B12

 

The bottom line is that it seems the best way to supplement to maximize absorption and maintain optimal blood levels of B12 is for vegan adults (as well as non-vegan adults over the age of 60) should consider supplementing with these doses of vitamin B12:

  • 50 µg twice a day OR
  • 150 µg once a day OR
  • 2,500 µg once a week

High doses of B12 are safe and there isn’t a tolerable upper limit that has been established. It is best to undergo testing regularly and adjust the dose as necessary.

 

The post Vitamin B12 Recommendations appeared first on Plant Based Dietitian.

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The 3 Vitamins that Prevent Brain Loss

The 3 Vitamins that Prevent Brain Loss.jpeg

By our seventies, one in five of us will suffer from cognitive impairment. Within five years, half of those cognitively impaired will progress to dementia and death. The earlier we can slow or stop this process, the better.

Although an effective treatment for Alzheimer's disease is unavailable, interventions just to control risk factors could prevent millions of cases. An immense effort has been spent on identifying such risk factors for Alzheimer's and developing treatments to reduce them.

In 1990, a small study of 22 Alzheimer's patients reported high concentrations of homocysteine in their blood. The homocysteine story goes back to 1969 when a Harvard pathologist reported two cases of children, one dating back to 1933, whose brains had turned to mush. They both suffered from extremely rare genetic mutations that led to abnormally high levels of homocysteine in their bodies. Is it possible, he asked, that homocysteine could cause brain damage even in people without genetic defects?

Here we are in the 21st century, and homocysteine is considered "a strong, independent risk factor for the development of dementia and Alzheimer's disease." Having a blood level over 14 (µmol/L) may double our risk. In the Framingham Study, researchers estimate that as many as one in six Alzheimer's cases may be attributable to elevated homocysteine in the blood, which is now thought to play a role in brain damage and cognitive and memory decline. Our body can detoxify homocysteine, though, using three vitamins: folate, vitamin B12, and vitamin B6. So why don't we put them to the test? No matter how many studies find an association between high homocysteinea and cognitive decline, dementia, or Alzheimer's disease, a cause-and-effect role can only be confirmed by interventional studies.

Initially, the results were disappointing. Vitamin supplementation did not seem to work, but the studies were tracking neuropsychological assessments, which are more subjective compared to structural neuroimaging--that is, actually seeing what's happening to the brain. A double-blind randomized controlled trial found that homocysteine-lowering by B vitamins can slow the rate of accelerated brain atrophy in people with mild cognitive impairment. As we age, our brains slowly atrophy, but the shrinking is much accelerated in patients suffering from Alzheimer's disease. An intermediate rate of shrinkage is found in people with mild cognitive impairment. The thinking is if we could slow the rate of brain loss, we may be able to slow the conversion to Alzheimer's disease. Researchers tried giving people B vitamins for two years and found it markedly slowed the rate of brain shrinkage. The rate of atrophy in those with high homocysteine levels was cut in half. A simple, safe treatment can slow the accelerated rate of brain loss.

A follow-up study went further by demonstrating that B-vitamin treatment reduces, by as much as seven-fold, the brain atrophy in the regions specifically vulnerable to the Alzheimer's disease process. You can see the amount of brain atrophy over a two-year period in the placebo group versus the B-vitamin group in my Preventing Brain Loss with B Vitamins? video.

The beneficial effect of B vitamins was confined to those with high homocysteine, indicating a relative deficiency in one of those three vitamins. Wouldn't it be better to not become deficient in the first place? Most people get enough B12 and B6. The reason these folks were stuck at a homocysteine of 11 µmoles per liter is that they probably weren't getting enough folate, which is found concentrated in beans and greens. Ninety-six percent of Americans don't even make the minimum recommended amount of dark green leafy vegetables, which is the same pitiful number who don't eat the minimum recommendation for beans.

If we put people on a healthy diet--a plant-based diet--we can drop their homocysteine levels by 20% in just one week, from around 11 mmoles per liter down to 9 mmoles per liter. The fact that they showed rapid and significant homocysteine lowering without any pills or supplements implies that multiple mechanisms may have been at work. The researchers suggest it may be because of the fiber. Every gram of daily fiber consumption may increase folate levels in the blood nearly 2%, perhaps by boosting vitamin production in the colon by all our friendly gut bacteria. It also could be from the decreased methionine intake.

Methionine is where homocysteine comes from. Homocysteine is a breakdown product of methionine, which comes mostly from animal protein. If we give someone bacon and eggs for breakfast and a steak for dinner, we can get spikes of homocysteine levels in the blood. Thus, decreased methionine intake on a plant-based diet may be another factor contributing to lower, safer homocysteine levels.

The irony is that those who eat plant-based diets long-term, not just at a health spa for a week, have terrible homocysteine levels. Meat-eaters are up at 11 µmoles per liter, but vegetarians at nearly 14 µmoles per liter and vegans at 16 µmoles per liter. Why? The vegetarians and vegans were getting more fiber and folate, but not enough vitamin B12. Most vegans were at risk for suffering from hyperhomocysteinaemia (too much homocysteine in the blood) because most vegans in the study were not supplementing with vitamin B12 or eating vitamin B12-fortified foods, which is critical for anyone eating a plant-based diet. If you take vegans and give them B12, their homocysteine levels can drop down below 5. Why not down to just 11? The reason meat-eaters were stuck up at 11 is presumably because they weren't getting enough folate. Once vegans got enough B12, they could finally fully exploit the benefits of their plant-based diets and come out with the lowest levels of all.

This is very similar to the findings in my video Vitamin B12 Necessary for Arterial Health.

For more details on ensuring a regular reliable source of vitamin B12:

There are more benefits to lowering your methionine intake. Check out Methionine Restriction as a Life Extension Strategy and Starving Cancer with Methionine Restriction.

For more on brain health in general, see these videos:

In health,

Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Image Credit: Thomas Hawk / Flickr. This image has been modified.

Original Link

The 3 Vitamins that Prevent Brain Loss

The 3 Vitamins that Prevent Brain Loss.jpeg

By our seventies, one in five of us will suffer from cognitive impairment. Within five years, half of those cognitively impaired will progress to dementia and death. The earlier we can slow or stop this process, the better.

Although an effective treatment for Alzheimer's disease is unavailable, interventions just to control risk factors could prevent millions of cases. An immense effort has been spent on identifying such risk factors for Alzheimer's and developing treatments to reduce them.

In 1990, a small study of 22 Alzheimer's patients reported high concentrations of homocysteine in their blood. The homocysteine story goes back to 1969 when a Harvard pathologist reported two cases of children, one dating back to 1933, whose brains had turned to mush. They both suffered from extremely rare genetic mutations that led to abnormally high levels of homocysteine in their bodies. Is it possible, he asked, that homocysteine could cause brain damage even in people without genetic defects?

Here we are in the 21st century, and homocysteine is considered "a strong, independent risk factor for the development of dementia and Alzheimer's disease." Having a blood level over 14 (µmol/L) may double our risk. In the Framingham Study, researchers estimate that as many as one in six Alzheimer's cases may be attributable to elevated homocysteine in the blood, which is now thought to play a role in brain damage and cognitive and memory decline. Our body can detoxify homocysteine, though, using three vitamins: folate, vitamin B12, and vitamin B6. So why don't we put them to the test? No matter how many studies find an association between high homocysteinea and cognitive decline, dementia, or Alzheimer's disease, a cause-and-effect role can only be confirmed by interventional studies.

Initially, the results were disappointing. Vitamin supplementation did not seem to work, but the studies were tracking neuropsychological assessments, which are more subjective compared to structural neuroimaging--that is, actually seeing what's happening to the brain. A double-blind randomized controlled trial found that homocysteine-lowering by B vitamins can slow the rate of accelerated brain atrophy in people with mild cognitive impairment. As we age, our brains slowly atrophy, but the shrinking is much accelerated in patients suffering from Alzheimer's disease. An intermediate rate of shrinkage is found in people with mild cognitive impairment. The thinking is if we could slow the rate of brain loss, we may be able to slow the conversion to Alzheimer's disease. Researchers tried giving people B vitamins for two years and found it markedly slowed the rate of brain shrinkage. The rate of atrophy in those with high homocysteine levels was cut in half. A simple, safe treatment can slow the accelerated rate of brain loss.

A follow-up study went further by demonstrating that B-vitamin treatment reduces, by as much as seven-fold, the brain atrophy in the regions specifically vulnerable to the Alzheimer's disease process. You can see the amount of brain atrophy over a two-year period in the placebo group versus the B-vitamin group in my Preventing Brain Loss with B Vitamins? video.

The beneficial effect of B vitamins was confined to those with high homocysteine, indicating a relative deficiency in one of those three vitamins. Wouldn't it be better to not become deficient in the first place? Most people get enough B12 and B6. The reason these folks were stuck at a homocysteine of 11 µmoles per liter is that they probably weren't getting enough folate, which is found concentrated in beans and greens. Ninety-six percent of Americans don't even make the minimum recommended amount of dark green leafy vegetables, which is the same pitiful number who don't eat the minimum recommendation for beans.

If we put people on a healthy diet--a plant-based diet--we can drop their homocysteine levels by 20% in just one week, from around 11 mmoles per liter down to 9 mmoles per liter. The fact that they showed rapid and significant homocysteine lowering without any pills or supplements implies that multiple mechanisms may have been at work. The researchers suggest it may be because of the fiber. Every gram of daily fiber consumption may increase folate levels in the blood nearly 2%, perhaps by boosting vitamin production in the colon by all our friendly gut bacteria. It also could be from the decreased methionine intake.

Methionine is where homocysteine comes from. Homocysteine is a breakdown product of methionine, which comes mostly from animal protein. If we give someone bacon and eggs for breakfast and a steak for dinner, we can get spikes of homocysteine levels in the blood. Thus, decreased methionine intake on a plant-based diet may be another factor contributing to lower, safer homocysteine levels.

The irony is that those who eat plant-based diets long-term, not just at a health spa for a week, have terrible homocysteine levels. Meat-eaters are up at 11 µmoles per liter, but vegetarians at nearly 14 µmoles per liter and vegans at 16 µmoles per liter. Why? The vegetarians and vegans were getting more fiber and folate, but not enough vitamin B12. Most vegans were at risk for suffering from hyperhomocysteinaemia (too much homocysteine in the blood) because most vegans in the study were not supplementing with vitamin B12 or eating vitamin B12-fortified foods, which is critical for anyone eating a plant-based diet. If you take vegans and give them B12, their homocysteine levels can drop down below 5. Why not down to just 11? The reason meat-eaters were stuck up at 11 is presumably because they weren't getting enough folate. Once vegans got enough B12, they could finally fully exploit the benefits of their plant-based diets and come out with the lowest levels of all.

This is very similar to the findings in my video Vitamin B12 Necessary for Arterial Health.

For more details on ensuring a regular reliable source of vitamin B12:

There are more benefits to lowering your methionine intake. Check out Methionine Restriction as a Life Extension Strategy and Starving Cancer with Methionine Restriction.

For more on brain health in general, see these videos:

In health,

Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Image Credit: Thomas Hawk / Flickr. This image has been modified.

Original Link

Three Things To Know About Vitamin B12

You can get all of your essential nutrients* on a thoughtful plant-based diet…except for vitamin B12. *Vitamin D is a nutrient our bodies were designed to attain via the sun. Though it is a common deficiency worldwide, this is not an issue exclusive to vegans. Here are Three Things To Know About Vitamin B12….in collaboration with …

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