Final answer:
Nicotinic acid (vitamin B3) has an effect on cholesterol levels by reducing LDL and VLDL levels and raising HDL levels, which improves the overall cholesterol profile and reduces the risk of heart disease.
Step-by-step explanation:
Nicotinic acid, also known as niacin or vitamin B3, has an effect on cholesterol levels. Option c) is correct. Nicotinic acid reduces the levels of LDL (low-density lipoprotein) and VLDL (very low-density lipoprotein) cholesterol, which are considered bad cholesterol. At the same time, nicotinic acid raises the levels of HDL (high-density lipoprotein) cholesterol, which is considered good cholesterol. This combination helps to improve the overall cholesterol profile and reduce the risk of heart disease.