Niacin seems to reduce the release of histamine, so it can help to reduce allergic reactions such as those of hayfever, eczema, urticaria and sinusitis.
Daily supplements of niacin can reduce the appearance of acne rosacea, the reddening of the face that occurs in some menopausal women.
Niacin supplements may help the body to produce more protective “HDL” cholesterol, which in turn helps reduce blocking of the arteries. Its use in diabetics has, however, been controversial. Some scientists feared that it could raise blood sugar levels. But a recent study has suggested that niacin can be safely used to treat cholesterol levels in those with diabetes.