You can safely take more than one B-complex vitamin per day. I normally take one B-100 time-release tablet in the morning. I will sometimes take another one in the evening before I go to sleep. When I do, I often wake up feeling more refreshed and energized. So, I don't feel that taking one in the morning and another at night is such a bad idea. Remember, all B vitamins are water-soluble, so whatever you have taken in the morning has long been excreted from your body by evening.
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