Unfortunately, you can't lower your cholesterol by taking a vitamin supplement -- to have such an effect it must be taken in doses well above the daily vitamin requirement. Although nicotinic acid is inexpensive and available over the counter, never take it for cholesterol reduction without a healthcare professional's oversight because of potential side effects.
Niacin also widens blood vessels, making flushing and hot flashes frequent side effects. These side effects may be reduced by taking the drug with meals or by taking aspirin or a similar medication with nicotinic acid. The extended release form, available by prescription as Niaspan, results in less flushing and liver toxicity than the immediate or sustained release forms.
Nicotinic acid can also intensify the effect of high blood pressure medication and produce various gastrointestinal problems -- nausea, indigestion, gas, vomiting, diarrhea and activation of peptic ulcers. Serious side effects include liver problems, gout and high blood sugar, with risk rising in tandem with the dose.
This drug may not be prescribed if you have diabetes because it can raise blood sugar slightly. If you have diabetes, talk about the pros and cons with your healthcare professional.