Here you have told you take oxylite pro and some vitamin tablets too. You have also inform that you are not over weight. Then I would like to know for what resion you are taking oxylite pro. Because it helps to improve metabolism in body but along with that it also have side effects of constipation, muscle twitching, restlessness, heart attack etc. So this can also cause back pain issue. I suggest if possible you should avoid this oxylite pro and to improve metabolism you can take vitamine b rich diet and do exercise like running and cycling as well paying on ground as much as you can. Next is I suggest to check with physio and if you have only muscular pain at back due to spinal muscle weakness then do regular back exercises as well initially you can also take some physiotherapy treatment for relaxing your soft tissues at spinal level. Later doing spinal exercises will help you for improving strength and stamina of your spine. Here I also suggest to take suggestion on postural correction from physio. If you have pain from your back to your legs along with numbness and tingling sensation then you need to get MRI of your lumbosacral spine and need to check the issues related with disc and nerve. Here if there is major problem showing in report you need to take suggestion from orhopedic doctor and then physiotherapist. For major issue orthopedic doctor will suggest for surgical correction and for mild to moderate he will suggest to follow physiotherapy. In both cases doing spinal exercises are must for long term relief. Take care