What is the expected effect of niacin on cholesterol levels?

Niacin, also known as vitamin B3, has a well-established role in lipid management, particularly in the modulation of cholesterol levels. The correct response highlights that niacin reduces LDL (low-density lipoprotein) cholesterol and triglycerides while simultaneously raising HDL (high-density lipoprotein) cholesterol levels.

Niacin's mechanism of action involves the inhibition of lipolysis in adipose tissue, which reduces the availability of free fatty acids for liver uptake. This leads to a decrease in the production of VLDL (very low-density lipoprotein) by the liver, which subsequently lowers LDL cholesterol levels due to their interconnected metabolism. Furthermore, niacin has the unique ability to increase HDL cholesterol, often referred to as "good" cholesterol, which plays a protective role against cardiovascular disease. The elevation of HDL cholesterol is one of the most notable benefits of niacin, as it helps in the reverse transport of cholesterol, carrying it away from peripheral tissues back to the liver for excretion.

When assessing the other choices, they do not align with the pharmacological actions of niacin. For instance, raising LDL cholesterol or having no effect on cholesterol levels directly contradicts the known effects of niacin, which are firmly established through clinical studies. Similarly,