Friday, August 12, 2005

Take a Supplement? Hey, Why Not Eat Food?

The Harvard Health Newsletter this week reported that Vitamin B12 deficiency is the most common nutritional deficiency in the developing world and possibly in the United States as well.

Say what? In the land of plenty, you may be wondering just how it is even possible that such a deficiency occurs!

For starters, we're told to limit our intake of red meat and avoid too many animal products in our diet - and those that we do eat, well, we're told they should be low-fat products. But, the Harvard Health Newsletter doesn't even address this obvious possible connection to B12 deficiency. Instead they attribute the deficiency on normal aging and eating a vegetarian/vegan diet.

Why they chose not to even state the obvious is beyond me. The only reliable unfortified sources of vitamin B12 are meat, fish, dairy products and eggs.

Vitamin B12 deficiency doesn't happen overnight. In fact it takes years and years to creep up on you. Vitamin B12 is stored in small amounts by the body. Total body store is 2-5mg in adults. Around 80% of this is stored in the liver. Vitamin B12 is excreted in the bile and is effectively reabsorbed. This is known as enterohepatic circulation. The amount of B12 excreted in the bile can vary from 1 to 10ug (micrograms) a day. People on diets low in B12, including vegans and some vegetarians, may be obtaining more B12 from reabsorption than from dietary sources.

Reabsorption is the reason it can take more than 10-years for deficiency disease to develop in people changing to diets low or absent of Vitamin B12. In comparison, if B12 deficiency is due to a failure in absorption it can take just 3 years or less for deficiency disease to occur.

Why do we need Vitamin B12?
  • support for the production of red blood cells
  • prevention of anemia
  • allow nerve cells to develop properly
  • help your cells metabolize protein, carbohydrate, and fat

What can indicate a need for more high-vitamin B12 foods?

  • red or sore tongue
  • tingling or numbness in feet
  • nervousness
  • heart palpitations
  • depression
  • memory problems
  • dandruff
  • decreased blood clotting
  • decreased reflexes
  • paleness
  • depression
  • difficulty swallowing
  • fatigue
  • tingling in feet
  • weakness
  • weak pulse
  • menstrual problems

How do other nutrients interact with vitamin B12?

Vitamin B6 is required for proper absorption of vitamin B12, and deficiency of vitamin B6 has been shown to impair B12 absorption in animal studies.

Conversion of vitamin B12 from its non-active into its biologically active form requires the presence of vitamin E. Individuals at risk for vitamin E deficiency may show signs of vitamin B12 deficiency as well.

Contrary to research from the mid 1970s, supplemental doses of vitamin C above the 500 milligram level do not appear to compromise B12 function.

Excessive intake of folic acid can mask B12 deficiencies, and individuals at risk for vitamin B12 deficiency who are also taking folic acid in supplement form should consult with their healthcare practitioner.

The most recent Recommended Dietary Allowances (RDAs) for vitamin B12 were set in 1998 by the National Academy of Sciences. The RDAs were established for all persons 1 year of age and older. For infants under the age of 1 year, Adequate Intake (AI) levels were set. These AI and RDA guidelines are as follows:

  • 0-6 months: 400 nanograms
  • 6-12 months: 500 nanograms
  • 1-3 years: 900 nanograms
  • 4-8 years: 1.2 micrograms
  • males 9-13 years: 1.8 micrograms
  • males 14 years and older: 2.4 micrograms
  • females 9-13 years: 1.8 micrograms
  • females 14 years and older: 2.4 micrograms
  • Pregnant females of any age: 2.6 micrograms
  • Lactating females of any age: 2.8 micrograms

Vitamin B12 deficiency is serious stuff. While taking a supplement may help boost levels back to normal in the body, you're still better off eating real food and choosing foods that contain high levels of B12 - like liver, beef, snapper, shrimp, snapper, scallops, chinook salmon, lamb, cod, halibut, venison, milk, yogurt and eggs.

If you're avoiding red meat and eggs, consider the fish selections above!

Keep in mind, while the Dietary Guidelines for Americans [DGA] encourage you to limit your animal proteins to 5 to 6 ounces each day, this is simply not enough to meet and/or exceed your requirement for Vitamin B12. I've been saying for some time now that the DGA is too low in a number of nutrients for health and well-being. This here is a clear example of how the recommendations to limit animal proteins is potentially affecting health in the United States - if you follow the DGA and limit your animal proteins, you're limiting your intake of Vitamin B12 - a vitamin critical for long-term health!

6 comments:

  1. Actually your article overlooks two important aspects: Most people with vitamin B12 deficiancy lack a protein in their stomach called intrinsic factor due to genetic issues or age.

    It doesn't matter how many animals these people ingest, since they physically can't extract the B12 from the meat, it passes their body without being absorbed. These people MUST take supplements, which don't rely on the intrinsic factor regardless if oral or otherwise.

    Second point: B12 is *always* of bacteriological origin, bacteria excrete B12 inside the bodies of the animals, including us. The problem with bacteria in humans is that they reside in the lower bowels where the B12 can't be absorbed, so our B12 "factory" is wasted, literally. The reason why e.g. the meat of killed cows contains B12, is because the bacteria reside higher up in the intestinal tract and hence their B12 gets absorbed.

    It is great that we can harvest cultures of these bacteria who produce B12 in the petri dish for us - we do not rely on killing animals.

    Which brings me to my closing point. Because we can culture these bacteria to produce B12, the fortification of B12 is probably the most naturally produced vitamin that exists, comparable to bakers yeast.

    So we vegans can integrate a completley natural source of B12 without sacrificing our health for our ethics, nor needing to sacrifice the health of animals by eating them.

    Because what most people forget in the "meat is healthy" discussion is, well, that it is not healthy. Being shot in the head. hung upside down on your lower legs, having your throat cut, intestine ripped out, hacked into small pieces and displayed in styrofoam trays in the supermarkted isn't really healthy.

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  2. Unfortunately, this vegan, as others, seems to make up their own logic as they go along. Not healthy? For whom? Obviously these practices aren't healthy for the ANIMAL IN QUESTION! That's a given. But this has no bearing on human health. B12 is just one of the many excellent nutrients found primarily or exclusively in animal products. We evolved to eat meat along with plants. Twisted logic will not save you from these facts. I give you your ethical conundrum, but your attempts to wrestle other issues like science and nutrition to conform to this idea that veganism is somehow more "healthy" than a low-carb whole-foods/organic approach is just not going work. I certainly think that we can choose farming practices that are more sustainable and "healthy" for all involved, and this is why I choose organic as much as possible. But I fear that as with most vegans your ethical stance will prevent you from seeing that anything other than full vegetarianism has any value whatsoever...

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  3. Yup...agree with Levi--there's always a blurring of issues there--I know this first hand because I had the nerve once to post an opinion about eating life-sustaining protein via animals on a message board, and don't ask what wrath I incurred from the vegans/vegetarians, etc. Not all, but the ones I run into are almost always militant on the ethical thing. Tough crowd.
    Adam

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  4. Vegan - thanks for your comments. My article was highlighting the omission in the Harvard Health Newsletter of the dietary aspects of vitamin B12 deficiency in those who are not vegan/vegetarian or lacking intrinsic factor.

    The newsletter adequately addressed those issues.

    My commentary highlighted one missing aspect that was overlooked and not included in the newsletter - that it is rather easy to miss the RDA for B12 when you're eating an omnivore diet and following the dietary guidelines and thus limiting animal proteins each day while avoiding red meat and eggs.

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  5. Many consumers of nutritional supplements do not realize that there is an impending danger to their Right to take nutritional supplements, including Vitamin B12. Codex Alimentarius, or 'Codex' for short, a part of the Central American Free Trade Agreement, CAFTA, could result in an international body, the World Trade Center (WTC), restricting or banning the personal use of nutritional supplements in order to ‘harmonize’ U.S. law to international standards. Supplement use is severely restricted in many European countries. To prevent this from happening here, consider supporting Dr. Ron Paul for the presidency of the US. Ron Paul understands that individuals have rights and, as a Congressman, has introduced legislation to protect people's right to take nutritional supplements. Check it out at http://www.ronpaul2008.com/

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  6. Anonymous11:12 AM

    Actually, raising animals for meat has a huge carbon footprint, a huge pool of natural resource depletion, a serious waste disposal problem (see hog farms for example), and further complications brought about by hormones/antibiotics and pathogens (i.e. BSE, or Mad Cow Disease). None of these things are healthy for humans, and in that sense the eating of meat by others directly impacts the health of people who choose to be vegetarian or vegan.

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