then why use prescription drug Statins which could interfere liver functions?
Ah, good question.
Niacin is not as benign as it may seem. Even though it is a water-soluble vitamin; the doses required to lower LDL and Triglycerides while raising HDL are quite large. We have to consider that at high doses, Niacin has a side-effect profile comparable to many prescription agents. One such side effect, which is quite common, is flushing – where the skin turns red and may become warm and painful. Although this seems like a mild effect, many patients cannot tolerate it and must stop taking Niacin.
Also consider that the level of effect with Niacin is not nearly as great as with the statins. High LDL and triglycerides, and Low HDL are all associated with cardiovascular disease; which may cause serious morbidity. Many americans have levels very far away from goal, and need to be treated aggressively – statins are the answer here.
Finally, a simple answer is ease of use. Niacin is taken twice to three times a day, on a up-titrating scale – and often must be taken with aspirin to prevent flushing. Like i said earlier, these require large doses (usually about 4 pills per dose). So we're talking 15 pills a day (4 Niacin/dose + 1 Aspirin/dose) to get to a level that may be less than that achieved by taking 1 Statin pill!