The Starch Solution (26 page)

For those who must take vitamin D supplements, such as elderly people who are unable to get outdoors or use a tanning bed, 200 IU per day should be adequate. This is compared with the commonly recommended levels of 2,000 to 4,000 IU per day of over-the-counter vitamin D to correct low vitamin D blood levels. Vitamin D
₂
is as effective as vitamin D
₃
in maintaining circulating concentrations of 25-hydroxyvitamin D.
⁶²
Taking 10,000 IU or more per day can cause vitamin D toxicity.

Defending eating habits seems to be a primal instinct. These days, Westerners are running out of excuses for their gluttony. Well-read people no longer believe meat is necessary to meet our protein needs, or that milk is the favored source of calcium. With the crumbling of these two time-honored battlefronts, the vitamin B
₁₂
issue has become the trendy argument against being vegan. Since the usual dietary source of vitamin B
₁₂
for omnivores is meat, the obvious conclusion is that those who choose to avoid eating it are destined to become deficient in B
₁₂
. There is a grain of truth in this concern, but an otherwise healthy vegan’s risk of developing
a disease
from B
₁₂
deficiency is extremely rare—less than one chance in a million. Subclinical, metabolic changes may be seen, but actual disease is exceedingly uncommon.

The human body has evolved with highly efficient and unique mechanisms to absorb, utilize, and conserve this vitamin. Our daily requirement is less than 3 micrograms (a microgram is one-millionth of a gram).
⁶³
By design, we need be exposed to only minuscule amounts of this essential nutrient. Typically, the liver stores 2 to 5 milligrams (or 2,000 to 5,000 micrograms) of B
₁₂
, at least a 3-year reserve. The body has many efficiency mechanisms, including reabsorbing the vitamin in the small intestine and recirculating it for future use. This means it could take you 20 to 30 years after adopting a vegan diet to become B
₁₂
deficient.
⁶⁴
This assumes you take in no new vitamin B
₁₂
, which is all but impossible since, even on a vegan diet, you will take in some B
₁₂
through bacterial sources on your food, in your gut, and in the environment, even if you aren’t trying.

There is evidence suggesting that during pregnancy and nursing, a mother is more dependent on B
₁₂
from her diet as her stored B
₁₂
is less available for the baby.
⁶⁵
During these crucial times, a vegan woman should take a B
₁₂
supplement.

Although vitamin B
₁₂
is found in animal foods, neither animals nor plants synthesize it. Bacteria make vitamin B
₁₂
. The intestines of animals, especially ruminants, such as cows, goats, and sheep, are populated with B
₁₂
-synthesizing bacteria. Animals store it in their tissues, and it gets passed up the food chain when one animal eats another. From the mouth to the anus, the human gut contains bacteria that synthesize vitamin B
₁₂
.
⁶⁶
These bacteria are an important reason that disease from B
₁₂
deficiency occurs so rarely, even among lifelong, dedicated vegans. The colon contains the greatest number of bacteria and is where most of our intestinal B
₁₂
is produced. However, because B
₁₂
is absorbed in the ileum, upstream of the colon, this plentiful source of B
₁₂
is not immediately available for absorption.

Feces from cows, chickens, sheep, pigs, and people contain large amounts of active B
₁₂
. Until recently, most people lived in close contact with their farm animals, meaning that they consumed plenty of B
₁₂
left as bacterial residue, and also obtained B
₁₂
from their unsanitized vegetables.

The lack of vitamin B
₁₂
is the one blemish on an otherwise perfect diet that holds out hope for preventing or curing our most common chronic diseases. This blemish is not because a plant-based diet is somehow lacking, but rather because we have developed unnatural conditions by sanitizing our surroundings with fanatical washing, powerful cleansers, antiseptics, and antibiotics. The rare case of B
₁₂
deficiency may be one important consequence of too much cleanliness. Regardless, I recommend supplementation with vitamin B
₁₂
.

The effects of B
₁₂
deficiency are observed first in the blood and then in the nervous system. In the blood, the deficiency shows up as megaloblastic
anemia, characterized by very large blood cells. Even when the megaloblastic anemia is severe, the low red blood cell count doesn’t typically cause problems for the patient, and the anemia is
always
cured with vitamin B
₁₂
supplementation.

The most common nervous system symptoms of B
₁₂
deficiency are numbness and tingling in the hands and feet. In the early stages of the deficiency, these neurological problems are entirely reversible. However, prolonged and severe deficiency can cause more serious and lasting nerve damage.

All in all, the risk of vitamin B
₁₂
deficiency is quite remote. On the other hand, eating lots of the foods that are highest in B
₁₂
means a diet rich in fatty animal foods, which hands you a 50 percent chance of dying prematurely from a heart attack or stroke, a one in six chance of developing prostate cancer (if you are male), and a one in seven chance of getting breast cancer (if you are female). In addition, this same diet increases your chances of obesity, diabetes, osteoporosis, constipation, indigestion, and arthritis. You can see these consequences of a rich, typically American, B
₁₂
-sufficient diet every day. You probably also know some vegetarians and vegans, but have you ever met one who has suffered from anemia or nervous system damage as a result of his or her diet? I doubt it.

Regardless of the minimal risk of vitamin B
₁₂
deficiency, I recommend taking a vitamin B
₁₂
supplement. In fact, it is the
only
supplement I recommend. I make this recommendation largely to plug the one hole critics might focus on in the otherwise exceptional diet I recommend, as well as protect against the minuscule risk of harm.

Here’s my specific recommendation: If you strictly follow the McDougall Diet in
The Starch Solution
or another vegan diet for more than 3 years, or if you are pregnant or nursing, I suggest you take a daily supplement of 5 micrograms of vitamin B
₁₂
.

When you go to purchase a supplement, you will find that the pills sold in stores typically contain not 5 micrograms but 500 to 5,000 micrograms (0.5 to 5 milligrams). These high concentrations are meant to correct B
₁₂
deficiency in people who may be unable to absorb it normally.
^67
,
68
Fortunately for the rest of us, these excessive quantities of B
₁₂
appear to be safe and nontoxic. If you are an otherwise healthy vegan and are using typical dosages of B
₁₂
(500 micrograms or more per pill), a weekly, rather than daily, dose of this vitamin will be more than sufficient.

Please check the bottle: B
₁₂
is often sold as cyanocobalamin, which some researchers have questioned for treating vitamin B
₁₂
deficiency, especially neurological problems. The methylcobalamin and hydroxycobalamin forms of B
₁₂
are better choices.
⁶⁹
Also note that B
₁₂
-like substances found in food supplements such as spirulina and other algae are ineffective and not a reliable substitute for vitamin B
₁₂
.
⁷⁰

Fermented foods, such as tempeh and miso, are also unreliable sources.
⁷¹
Fortified foods, including some nutritional yeasts, may be reliable sources of B
₁₂
. The seaweed nori, used to wrap maki (sushi rolls, which can be made with vegetables and brown rice rather than fish), has been found to contain substantial amounts of active vitamin B
₁₂
thanks to symbiotic organisms that live on it, making nori a “most excellent source of vitamin B
₁₂
among edible seaweeds, especially for strict vegetarians.”
^71
–
73
If you have any question about your B
₁₂
status, I suggest that you check your B
₁₂
levels through blood testing; if they are adequate, recheck every 3 years.

In order to maximize your health and minimize the risk of any health problems, I recommend that you and your family follow a diet based on starches, vegetables, and fruits. Expose yourself to adequate sunshine and get a little exercise. To avoid the extremely rare chance of becoming a national headline, add a reliable B
₁₂
supplement. Failure to follow the starch-based diet that is the natural one for humans is the
reason that more than a billion people are overweight and sick today. Trying to fix modern-day health problems with supplements adds to the injury at great financial costs. Scientific facts and reasoning call for the blind and misguided faith placed in supplements to stop.

The attacks began when I was 41. Nausea and dizziness made the room spin so fast I couldn’t lift my head from the pillow. Our family doctor diagnosed an inner ear infection by phone, but the medicine he prescribed didn’t help. I remained incapacitated. Several days later, a friend drove my husband and me to the doctor. He referred me for an MRI and a visit with the neurologist, who delivered the decree as we sat in stunned silence: I had MS, multiple sclerosis.

The doctor drew a big X in the upper left-hand corner of his whiteboard, and another X in the middle, with a downward line between them. He tapped the higher X: This is where you are now. He pointed to the middle X: This is you in 5 years, in a wheelchair. He placed a final X in the lower right corner: This is 10 years from now; you will be bedridden. He scheduled me for a spinal tap, and when I refused the risky and painful test he threatened to remove my name from consideration for clinical drug trials, our only hope for a possible future cure.