<prompt> Which vitamin in large doses decreases triglyceride and cholesterol?Vitamin B1Nicotinic acidVitamin B12Riboflavin  <response>: Niacin and nicotinic acid is a vitamin. Niacin is conveed to its coenzyme forms NAD and NADPTreatment of hyperlipidemia:Niacin at doses of 1.5 gday or 100 times the Recommended Dietary Allowance or RDA strongly inhibits lipolysis in adipose tissue--the primary producer of circulating free fatty acids. The liver normally uses these circulating fatty acids as a major precursor for triacylglycerol synthesis. Thus, niacin causes a decrease in liver triacylglycerol synthesis, which is required for very-low-density lipoprotein VLDL, see p.231 production. Low-density lipoprotein LDL, the cholesterolrich lipoprotein is derived from VLDL in the plasma. Thus, both plasma tri acylglycerol in VLDL and cholesterol in VLDL and LDL are lowered. Therefore, niacin is paicularly useful in the treatment of Type IIb hyperlipoproteinemia, in which both VLDL and LDL are elevated. Ref: Lippincott, 5th edition, page no: 380 