Is it an acceptable alternative for a 68 year old very active male to take 1500mg non-flush niacin instead of 5mg crestor (rosuvastatin)?

Depends: It depends what lipids disorders need to be target. If the problem is HDL alone or the LDL is normal and you do not ned a statin like Crestor (rosuvastatin) then is ok, but if you have a high ldl, then this must be target first and then recheck the rest of the profile. I bet you will have more side effects from Niacin than from Crestor (rosuvastatin) 5 mg. Check with your doctor.