THE BLOG

Can't Beat Fatigue? You May Be Low in B12

09/07/2012 07:49 EDT | Updated 11/06/2012 05:12 EST
Flickr: Jerry Bunkers

Fatigue is one of the most common concerns that initially prompts a new patient to book an appointment at my clinic. While the cause can range from insomnia or excessive stress to food allergies or a hormonal imbalance, more often than not I find that low levels of vitamin B12 (and often iron, which can go hand in hand) are at least partially to blame.

Since it's a water-soluble vitamin, the body is unable to store extensive amounts of B12 and must therefore get a regular supply from the diet or supplements. This can be difficult for some people, especially if you are vegetarian or vegans, or you have absorption issues (such as celiac or chrohn's disease). The good news is that it's also one of the easiest things to restore and replace.

Get your levels tested:

B12 contributes to brain function by lowering homocysteine. In fact, on your next trip to the doctor I would put it on your must-request list, especially if you are over the age of 30. It's useful to test vitamin B12 (optimal value: more than 600) and folic acid (optimal value: more than 1,000) at the same time, since these substances are involved in the process of metabolism necessary to reduce homocysteine levels along with vitamin B6 and a compound called trimethylglycine.

Homocysteine is an inflammatory protein that, if elevated in the blood, is a proven independent risk factor for heart disease, osteoporosis, Alzheimer's disease and stroke. If your homocysteine is too high, include a complex of vitamin B6, vitamin B12 and folic acid in your daily vitamin regime until your next physical exam. Optimal value for your blood test is less than 6.3 for homocysteine, while I find that most patients feel their best when their B12 levels are over 600 on their blood test.

Check your medications:

Many prescription and over-the-counter medications increase our need for certain vitamins and minerals. While these drugs may be beneficial in the treatment of a disease condition, they come with a nutritional cost. For example, the birth control pill causes a decrease in B12, along with zinc, folic acid, B6 and vitamin C. Metformin, which is used to treat diabetes, might reduce the absorption of vitamin B12 and small studies and research papers suggest that 10-30 per cent of patients who take metformin have experienced this. These medications can interfere with the absorption of vitamin B12 from food by slowing the release of hydrochloric acid into the stomach. If you have inadequate B12 levels to begin with, or are using these medications for a lengthy period of time you may be more susceptible to lowered vitamin B12 levels.

Daily dose of B12:

Not all vitamin B12 supplements are created equal. A compromised digestive system can affect your absorption of certain vitamins and minerals, so I prefer to boost a patient's vitamin B12 levels through lozenges or vitamin B12 injections -- both of these methods allow nutrients to bypass digestion and enter directly into the bloodstream.

When selecting a lozenge, look for hydroxocobalamin on the back of the label. When opting for injectible B12, you should request methylcobalamin -- it's the form found in food, which makes it easier for your body to absorb. I suggest taking 2,000 mcg to 4,000 mcg daily, either with or without food. The recommended daily intake of B12 from food is 2.4 mcg for adult women, 2.6 mcg for pregnant women, and 2.8 mcg for lactating women -- but absorption of B12 from food is much stronger than from supplements. I also highly recommend doing the HCL challenge, which is designed to restore the acidity levels of your stomach since low stomach acid can affect your ability to absorb many vitamins, including B12, from your food.

For optimal results, I recommend taking 2,000 mcg - 4,000 mcg daily either with or without food. In addition, you can boost your vitamin B12 levels by including the following foods in your diet:

  • Liver, beef, braised, one slice: 48.0 micrograms (mcg) per serving
  • Clams, cooked, 3 ounces: 34.2 micrograms (mcg) per serving
  • Trout, rainbow, wild, cooked, 3 ounces: 5.4 micrograms (mcg) per serving
  • Salmon, sockeye, cooked, 3 ounces: 4.8 micrograms (mcg) per serving
  • Trout, rainbow, farmed, cooked, 3 ounces: 3.5 micrograms (mcg) per serving
  • Haddock, cooked, 3 ounces: 1.8 micrograms (mcg) per serving
  • Yogurt, plain, 1 cup: 1.4 micrograms (mcg) per serving
  • Beef, top sirloin, broiled, 3 ounces: 1.4 micrograms (mcg) per serving
  • Tuna, white, 3 ounces: 1.0 micrograms (mcg) per serving
  • Milk, 1 cup: 0.9 micrograms (mcg) per serving
  • Cheese, Swiss, 1 ounce: 0.9 micrograms (mcg) per serving
  • Ham, cured, roasted, 3 ounces: 0.6 micrograms (mcg) per serving
  • Egg, large, one whole: 0.6 micrograms (mcg) per serving
  • Chicken, roasted, half breast: 0.3 micrograms (mcg) per serving