Instruct: Classify Amazon reviews into positive or negative sentiment
Query: You don't always notice until the bottle runs empty

I've always found it difficult to decipher the pro's and con's of daily vitamin consumption. The only thing I can offer is over the last month or so I've noticed a slight reduction in energy and focus. Overall I still feel decently healthy, however, it recently dawned on me that about 3 weeks ago I stopped taking these daily vitamins b/c my supply ran dry. Now it wouldn't be right to contribute this reduction in energy solely on the demise of my vitamin consumption but it would be safe to say it's very possible these vitamins may have been benefiting me all along. I'm placing another order regardless :)