These vitamins are tested when deficiencies are suspected. They act on the nervous system as well as on the coronary arteries. Vit. B6, B12 and Folate help reduce Homocysteine. Vitamin B3 helps increase HDL-C (good cholesterol). Vitamin B12 is important in nerve function and treatment for a type of blood anemia. Folate deficiency can also cause anemia. Vitamins and supplements should not be taken for 48 hours prior to testing for baseline.