The reason given: "Based on the collective evidence from several large cardiovascular outcome trials, the Agency has concluded that the totality of the scientific evidence no longer supports the conclusion that a drug-induced reduction in triglyceride levels and/or increase in HDL-cholesterol levels in statin-treated patients results in a reduction in the risk of cardiovascular events." The drug company discontinued the drugs. Contraindications
Prescription immediate release (Niacor) and extended release (Niaspan) niacin are contraindicated for people with either active or a history of liver disease because both, but especially Niaspan, have been associated with instances of serious, on occasion fatal, liver failure. Both products are contraindicated for people with existing peptic ulcer disease, or other bleeding problems because niacin lowers platelet count and interferes with blood clotting. Both products are also contraindicated for women who are pregnant or expecting to become pregnant because safety during pregnancy has not been evaluated in human trials. These products are contraindicated for women who are lactating because it is known that niacin is excreted into human milk, but the amount and potential for adverse effects in the nursing infant are not known. Women are advised to either not nurse their child or discontinue the drug. High-dose niacin has not been tested or approved for use in children under 16 years. Adverse effects
The most common adverse effects of medicinal niacin (500–3000 mg) are flushing (e.g., warmth, redness, itching or tingling) of the face, neck and chest, headache, abdominal pain, diarrhea, dyspepsia, nausea, vomiting, rhinitis, pruritus and rash.
Fortified foods and dietary supplements can also be consumed to ensure adequate intake. Food preparation
Niacin naturally found in food is susceptible to destruction from high heat cooking, especially in the presence of acidic foods and sauces. It is soluble in water, and so may also be lost from foods boiled in water. Food fortification
Countries fortify foods with nutrients to address known deficiencies. As of 2020, 54 countries required food fortification of wheat flour with niacin or niacinamide; 14 also mandate fortification of maize flour, and 6 mandate fortification of rice. From country to country, niacin fortification ranges from 1.3 to 6.0 mg/100 g.

As a dietary supplement
In the United States, niacin is sold as a non-prescription dietary supplement with a range of 100 to 1000 mg per serving. These products often have a Structure/Function health claim allowed by the US Food & Drug Administration (FDA). An example would be "Supports a healthy blood lipid profile." The American Heart Association strongly advises against the substitution of dietary supplement niacin for prescription niacin because of potentially serious side effects, which means that niacin should only be used under the supervision of a health care professional, and because manufacture of dietary supplement niacin is not as well-regulated by the FDA as prescription niacin. More than 30 mg niacin consumed as a dietary supplement can cause skin flushing. Face, arms and chest skin turns a reddish color because of vasodilation of small subcutaneous blood vessels, accompanied by sensations of heat, tingling and itching.