Tag: fertility

Vitamin B12 (cobalamin)

Overview

Vitamin B12, also called cobalamin, is one of 8 B vitamins. All B vitamins help the body convert carbohydrates into fuel (glucose), which is used to produce energy. These B vitamins, often referred to as B complex vitamins, also help the body use fats and protein. B complex vitamins are needed for healthy skin, hair, eyes, and liver. They also help the nervous system function properly. All B vitamins are water-soluble, meaning that the body does not store them and must be replenished every day.

Vitamin B12 is an especially important vitamin for maintaining healthy nerve cells, and it helps in the production of DNA and RNA, the body’s genetic material. Vitamin B12 also works closely with vitamin B9 (also called folate or folic acid) to help make red blood cells and to help iron work better in the body. Folate and B12 work together to produce S-adenosylmethionine (SAMe), a compound involved in immune function and mood.

Vitamins B12, B6, and B9 work together to control blood levels of the amino acid homocysteine. High levels of homocysteine are associated with heart disease.

Defficiency

Mild defficiency is relatively common with unwholesome diets and low stomach acid levels, which the body needs to absorb B12. Low levels of B12 can cause a range of symptoms including fatigue, shortness of breath, diarrhoea, nervousness, numbness, or tingling sensation in the fingers and toes. Severe deficiency of B12 causes nerve damage. Others at risk for B12 deficiency include:

  • Vegans, vegetarians who also don’t eat dairy or eggs – vitamin B12 is found only in animal products
  • People with problems absorbing nutrients, due to conditions such as Crohn’s disease, pancreatic disease, and people who have had weight loss surgery
  • People who are infected with Helicobacter pylori, an organism in the intestines that can cause ulcers. H. pylori damages stomach cells that make intrinsic factor, a substance the body needs to absorb B12
  • People with eating disorders
  • People with HIV
  • The elderly

Pernicious Anaemia

Pernicious anaemia is a type of anaemia that happens when stomach cells are not able to make intrinsic factor. Without intrinsic factor, your body cannot absorb vitamin B12. Symptoms include weakness, pale skin, diarrhoea, weight loss, fever, numbness or tingling sensation in the hands and feet, loss of balance, confusion, memory loss, and moodiness. Vitamin B12 supplements in high doses, either given as injections or orally, are prescribed to treat pernicious anaemia. Pernicious anaemia can be a dangerous condition and patients should always be co-treated with a doctor.

Heart Disease

Many studies suggest that people with high levels of the amino acid homocysteine are roughly 1.7 times more likely to develop coronary artery disease and 2.5 times more likely to have a stroke than those with normal levels. B complex vitamins, especially vitamins B9, B6, and B12, help lower homocysteine levels.

Age-Related Macular Degeneration

One large study found that women who took 1,000 mcg of vitamin B12 along with 2500 mcg of folic acid and 500 mg of vitamin B6 daily reduced their risk of developing AMD, an eye disease that can cause loss of vision.

Fatigue

Fatigue is one of the symptoms of a vitamin B12 deficiency. One small study, done several years ago, suggested that some people who were not deficient in B12 might gain more energy from B12 shots.  Please consider other causes and solutions for fatigue to provide wholesome advice.

Breast Cancer

Although there is no evidence that vitamin B12 alone reduces the risk of breast cancer, population studies have shown that women who get more folate in their diet have lower risk of breast cancer. Vitamin B12 works with folate in the body, so it may help contribute to a lesser risk. Another preliminary study suggested that postmenopausal women who had the lowest amounts of B12 in their diet had an increased risk for breast cancer.

Male Infertility

Studies suggest that vitamin B12 supplements may improve sperm counts and sperm mobility.

Dietary Sources

Vitamin B12 is found only in animal foods. Good dietary sources include fish, shellfish, dairy products, organ meats — particularly liver and kidney– eggs, beef, and pork.

Upper Limits

The Council for Responsible Nutrition recommends an upper limit of 3,000 µg (3 mg) per day although it acknowledges that no toxic effects of B12 have been encountered in humans or animals at any level of oral intake (Miller and Hayes 1982; IOM 1998). The CNR states that the overall evidence indicates that vitamin B12 is virtually nontoxic. D

Source

University of Maryland Medical Center