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The In’s & Out’s of Vitamin B-12 Deficiency

A severe B12 (cobalamin) deficiency will eventually result in anemia if uncorrected. Anemia refers to an insufficient number of healthy red blood cells, which impairs the ability of oxygen to be carried to your body’s tissues. Pernicious anemia – the type caused specifically by cobalamin deficiency – can gravely impair neurologic function. Subclinical deficiency is much more common, in which a low cobalamin level appears on a blood test, but has yet to cause anemia.

Recall from my previous post on vegetarian diets that absorption of vitamin B12 is dependent on intrinsic factor (IF), which is produced in the gut.  Causes of deficiency include inadequate dietary intake and impaired intestinal malabsorption, possibly due to lack of IF or insufficient  gastric acid secretion (as is the case in the elderly). If your blood labs do not improve after dietary manipulation or supplementation, speak with your doctor about other tests that can determine if your deficiency is related to malabsorption.

The severity of your B12 deficiency dictates the level of supplementation required. A B12 level less than 400 pg/mL may be cause for concern, but it’s all about lab value trends. Correction of vitamin B12 levels to within the acceptable range may simply require a daily multivitamin (that usually contains 6 µg per tablet). The recommended daily intake for American adults is 2.4 µg. Research shows that for people (like vegetarians) who have normal B12 absorption, doses greater than 5 µg per day exceed the binding capacity of IF and only a tiny fraction can be absorbed anyway.

On the other hand, a more critical deficiency may require several weeks of high-dose supplementation (e.g. 1,000 µg daily oral dose) to be taken under the direction of your doctor. Sublingual B12 supplements, which dissolve under your tongue, are very effective in delivering the nutrient directly to your bloodstream, similar to an injection. These oral supplements come in 1,000 or even 5,000 µg doses or more! “Mega-dosing,” however, is excessive for someone who is still only moderately low in B12. While no toxic level of B12 supplementation has been found to date, it’s always wise to stick with the lowest dose possible that will effectively achieve healthful results.

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Filed under Medical Conditions, Supplements, Vitamins & Minerals

Benefits of Fiber

Q: What exactly is ‘fiber’ and why is it so good for you?

A: Fiber is an indigestible carbohydrate, or a string of sugar units held together by bonds that human digestive enzymes cannot break. There are two types: soluble and insoluble fiber.

Food Sources

Soluble fiber: barley, oats, oat bran, rye, fruits (especially apples and citrus), beans, vegetables, seeds

Insoluble fiber: Brown rice, fruits, beans, seeds, vegetables (cabbage, carrots, brussels sprouts), wheat bran, whole grains

While fiber does not provide energy, it has many other beneficial effects:

1. Lowers blood cholesterol: Soluble fiber reduces cholesterol and the risk of heart disease by several mechanisms. (Note: This is why General Mills is able to claim that eating whole grain oat Cheerios can help lower your cholesterol.)

2. Maintains bowel function: Insoluble fiber speeds up the transit of food through your system, while soluble fiber slows it down.

3. Assists blood glucose control: Soluble fiber slows the absorption of glucose from the intestine into the blood stream, thereby preventing a spike (and crash) in blood glucose after a meal. This can lower the risk of type 2 diabetes.

4. Promotes weight management: Fiber makes you feel full and lessens hunger

5. May defend against colon and rectal cancer: Scientific studies are mixed, but insoluble fiber speeds up the removal of cancer-causing agents from the colon, while resident bacteria in the colon ferment soluble fiber, producing a beneficial compound that may help colon cells resist injury.

Recommended Intake: Since most fiber-rich foods supply a mixture of soluble and insoluble fiber, recommendations are given without regard to type. The American Dietetic Association suggests 20 – 35 grams of fiber daily, which is about twice the average intake. That said, don’t overload on fiber and make sure to increase fluid consumption as you gradually increase fiber intake.

Fruits, vegetables, whole grains and beans are among the best sources of fiber! Also, remember that fiber supplements are not necessarily substitutes for whole, fiber-rich foods.

Check the nutrition facts on the back of products to find out how much fiber is in one serving! Here are some examples:

½ cup whole grain barley – 3g fiber

½ cup instant oatmeal – 2g fiber

1 slice whole wheat bread – 3g fiber

1 slice white bread – 1g fiber

½ cup cooked brown rice – 2g fiber

½ cup cooked white rice – less than 1g fiber

¾ cup (2 oz) whole wheat penne pasta, dry – 6g fiber

¾ cup (2 oz) regular penne pasta, dry – 2g fiber


1 medium apple (with skin) – 3g fiber

1 medium pear (with skin) – 5g fiber

½ cup blackberries – 4g fiber

½ cup strawberries – 2g fiber

1 medium orange – 4g fiber

½ cup orange juice – less than 1g fiber

½ cup American grapes – less than 1g fiber


½ cup lentils – 8g fiber

½ cup chickpeas (garbanzo beans) – 5g fiber

½ cup black beans – 7.5g fiber


½ cup cooked broccoli – 2.5g fiber

1 medium artichoke – 10g fiber

1 medium baked potato (with skin) – 4.5g fiber

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Filed under Fruits and Vegetables, Grains, Heart Healthy Choices, Medical Conditions, Weight loss