Table 1.

Clinical trials conducted among migraine patients using riboflavin (vitamin B₂).

Study location	Control		Placebo		Duration of administration	Outcomes	P value	Reference
	Dose	Sample size	Dose	Sample size
Belgium	B2 (400 mg/day)	55	Placebo	55	3 months	59% of reduction in frequencies of migraine attack and days with headache	0.0120	[36]
USA	B2 (400 mg/day) + magnesium = (300 mg/day) + feverfew (100 mg/day)	24	25 mg/day of vitamin B2	24	3 months	50% or greater reduction in migraine in 40% of migraine patients	0.0006
						Days with migraine	0.0700	[45]
						Migraine index	0.0006
USA	B2 (400 mg/day) + magnesium = (300 mg/day) + feverfew (100 mg/day)	24	25 mg/day of vitamin B2	24	1 month	50% or greater in reduction of migraine in 33% of migraine patients	<0.0001
						Days with migraine	0.0400	[45]
						Migraine index	0.1000
Australia	B2 = 200 mg/day	21	Placebo	27	1 month	50% or greater reduction in headaches	0.1250	[46]
Italy	B2 (200 mg/day or 400 mg/day) randomly administered	41	Compared with baseline		6 months	50% or greater reduction in headache frequency among 68.4% of patients 50% or greater reduction in intensity of headache	<0.010	[47]
Netherlands	B2 (50 mg/day)	42	Placebo	42		Reduction in frequency of migraine attacks	0.4400	[48]
Germany	B2 (400 mg/day)	23	Compared with baseline		3 months	Frequency of headache	<0.0010
						Duration of attacks	0.0980	[37]
						Headache intensity	0.2960
Germany	B2 (400 mg/day)	23	Compared with baseline		6 months	Frequency of headache	0.0050
						Duration of attacks	0.0980	[37]
						Headache intensity	0.2960