The safety of over-the-counter niacin. A randomized placebo-controlled trial [ISRCTN18054903]

Table 4 Adverse events reported

Adverse Event	Niacin (n = 33)	Placebo (n = 35)	P-value
Composite of pruritus (head. neck, extremities or torso):	25 (75%)	0	<0.001
Composite of tingling (head, torso):	10 (30%)	0	<0.001
Unpleasant warmth or flushing:	33 (100%)	1	<0.001
Nausea	10 (30%)	1 (3%)	.005
Vomiting	4 (12%)	0	.005
Stomach cramps	2 (6%)	0	NS
Vertigo	4 (12%)	0	.05
Difficult breathing	2 (6%)	0	NS
Chills*	17 (52%)	0	< .0001
Pass stool	3 (9%)	0	NS
Heart palpitations	5 (15%)	0	.0228
Other	4 (12%)	1 (3%)	NS

* Chills are defined as shivering accompanied by the sensation of coldness and pallor of the skin.