HDL stands for high-density lipoprotein and is called 'good' cholesterol because it acts like a vacuum cleaner sucking up all the cholesterol it can find and transporting it back to the liver for excretion. LDL (low-density lipoprotein) particles have the opposite function – they deliver cholesterol from the liver to the cells that need it. Healthy levels for HDL are above 40 mg / dL for men and 50 mg / dL for women. However, if your LDL level is high, low levels of HDL can not gather up all the surplus cholesterol that is being transported by the LDL particles and not used by the cells. Here, much of this cholesterol may end up in artery-cell walls, constricting the artery, and restricting blood flow.
In cases where HDL levels in the blood are too low, it is possible to increase their number with niacin. In small quantities niacin, which is vitamin B3, helps the body perform certain functions. In large doses (2,000 mg or more per day), it can increase the number of HDL particles in the blood, in some cases by 35%, and helps remove more harmful cholesterol so lowering the risk of heart disease. This has been known for sometime and has been prescribed by many heart doctors to move their patients out of harm's way. It probably has not been well known to the public because of two reasons: currently the medical approach is to lower LDL levels, and the pharmaceutical companies – for monetary reasons – want a drug to do the job of raising HDL levels, and so far they have not been able to come up with one. Niacin is simple, but is not necessarily under pharmaceutical control so its role in raising HDL levels has not been made public.
The taking of mega doses of Niacin should not be done without under a doctor's care. This vitamin can hurt liver function and if you are taking other medications you may experience drug interactions. A doctor is required to monitor your progress and prevent any harmful side effects.