On Nutrition: Energy from B-vitamins?

“An elder citizen seeking more energy” writes: “Can (vitamin) B-12 taken orally be effective (for more energy) or must other B-vitamins be included?”

Here is the long answer to your short question:

B-vitamins taken orally (in food or supplements) can indeed be effective for energy production. That’s one of their main purposes -to help our cells derive energy from the foods we eat. B-vitamins also help produce red blood cells that feed our body oxygen and other nutrients.

A deficiency of vitamin B-12 – a condition called “megaloblastic anemia” – can cause fatigue and weakness. When this condition is corrected, energy levels can return to normal. Unless you have a deficiency, however, it is unlikely that additional vitamin B-12 will necessarily enhance your energy.

How to know if you have a deficiency of vitamin B-12? Your doctor can check with blood tests.

Here is some other interesting information about vitamin B-12 from the National Institutes of Health (NIH) Office of Dietary Supplements (ODS):

Vitamin B-12 is primarily found in foods of animal origin such as meat, fish, poultry, eggs, and dairy foods. When we eat these foods, B-12 is “freed” for use in our body by the action of stomach acid and enzymes. Synthetic vitamin B-12 – found in dietary supplements and fortified foods – is already in its “free” form.

Whether natural or synthetic, vitamin B-12 is absorbed into the body only when it combines with “intrinsic factor” – a substance formed in the cells of the stomach.

Some people can get plenty of vitamin B-12 in their diets and still have a deficiency of this vital nutrient, however. A condition called “pernicious anemia” destroys the stomach’s ability to produce intrinsic factor which prevents the absorption of B-12. People with this condition may require injections of vitamin B-12 to bypass the need for absorption through the stomach.

People most at risk for vitamin B-12 deficiency are those follow a strict vegetarian diet or have a reduced amount of stomach acid. And as we age, our stomachs produce less acid. For this reason, nutrition experts now recommend people older than 50 obtain most of their vitamin B-12 from foods with “free” vitamin B-12 such as fortified cereals and dietary supplements.

How much do we need? The Recommended Dietary Allowance (RDA) for healthy people over the age of 14 years is 2.4 micrograms of vitamin B-12 daily. Higher doses have not been found to be toxic since the body is able to limit how much it absorbs.

In answer to the second part of your questions, “other B-vitamins” include a complex of several compounds that are necessary to produce energy within the cells of our body. B-vitamins are found in a variety of foods including whole and fortified grains and cereals, beans and lentils, potatoes and bananas.

Why so many “B” vitamins? Scientists once thought they were just one vitamin. As new compounds were discovered, they were numbered as distinct vitamins including thiamin (B-1), riboflavin (B-2), B-6, and B-12.

Bottom line: B-12 supplements do not necessarily increase your energy unless you are correcting an existing deficiency. The most effective way to get the right balance of B-vitamins into your body is to eat a variety of foods that contain these vitamins. Dietary supplements are meant to “supplement” what may be deficient in your diet for one reason or the other.

(Barbara Quinn is a registered dietitian and certified diabetes educator at the Community Hospital of the Monterey Peninsula. Email her at bquinn@chomp.org.)