Vitamin B-12 supplements are beneficial for people deficient in the vitamin, WebMD reports. People at risk for Vitamin B-12 deficiency include people over 50, vegans, people suffering from Crohn's or celiac disease, HIV-positive people and those taking certain prescription drugs, such as prescription antacids, chemotherapy drugs and anti-seizure medications, states Healthline.
Vitamin B-12 assists in DNA production and ensures the production of healthy nerve and red blood cells, explains WebMD. Symptoms of Vitamin B-12 deficiency include shakiness, fatigue, muscle weakness, incontinence and stiff muscles, notes Healthline. Vitamin B-12 deficiency can cause megaloblastic anemia, a condition where the bone marrow produces large, immature blood cells that cannot provide oxygen to the body.
Researchers have studied the effectiveness of Vitamin B-12 supplementation to treat diseases, such as Alzheimer's disease, breast cancer, heart disease, high cholesterol and sickle cell disease with inconclusive results, notes WebMD. Studies have shown that Vitamin B-12 is ineffective at reducing the risk of lung cancer and stroke. Researchers have found that Vitamin B-12, along with folate and Vitamin B-6, reduces the risk of age-related macular degeneration in women with heart disease or are at high risk of heart disease.
Doctors recommend Vitamin B-12, along with folate, for individuals who have high homocysteine levels, although the evidence supporting the effectiveness of Vitamin-B-12 in treating the condition is conflicting, explains WebMD.