Research on the use of vitamin B-6 for specific conditions shows:

Heart and blood vessel disease and stroke. Researchers had previously believed that vitamin B-6, when combined with folic acid (vitamin B-9) and vitamin B-12, might prevent diseases of the heart and blood vessels by reducing the levels of an amino acid in the blood (homocysteine). However, studies show that the combination of these vitamins doesn't seem to reduce the risk or severity of cardiovascular disease and stroke.
Morning sickness. Vitamin B-6 might reduce the severity of morning sickness during pregnancy. If you have persistent nausea and vomiting, your pregnancy care provider might prescribe vitamin B-6 supplements.
Premenstrual syndrome (PMS). There is some evidence that vitamin B-6 might reduce symptoms of PMS; however, these studies are considered to be low quality.
Sideroblastic anemia. Vitamin B-6 is effective at treating this genetic type of anemia.