To preface this answer, I am NOT a pharmacist. However, in the pharmacology training I have had (in multiple programs) as well as being a pharmacy technician for a few years, the main reason a store will send back medications that are about to expire or are expired is due to liability, just like with food.
The medications you have (supplements) have an expiry date of April, but taking them should not harm you. (As every brand/medication is different, 'should' is used lightly). Usually the expiration date means that the effectiveness of the medication will lessen after that time, so the effects it has on your body will be weaker. Basically, if you take the recommended dose it may or may not work the same as it had in the past.
That being said, if you are concerned about safety of the medications/supplements, your best bet is to talk to your pharmacist or dispose of them properly and get a new bottle.