Blackmores Vitamin B6 is a one a day dose, formulated to help relieve symptoms of pre-menstrual tension in women. Blackmores Vitamin B6 Blackmores Vitamin B6 is a sustained release formula to supply the nutrients gradually over several hours. Convenient one-a-day dosage. Vitamin B6 may be of benefit for the relief of pre-menstrual symptoms such as breast tenderness, mild fluid[GH1] retention, irritability and fatigue.