Brief Answer:
Calcium supplements,bisphosphonates, physiotherapy

Detailed Answer:
Hi XXXXX,
Thanks for your query,
I think you must take care of osteopenia. You may take help of endocrinologist who may prescribe you bisphosphonates like etidronate or pamidronate along with calcium preparation. Spinal problem at L3 can be due to the same. and same may cause symptoms of neuropathy due to nerve root compression supplying the lower limbs.
You may visit physiotherapist for some back extension exercises which definitely benefits on a long term.
In the meantime you may take mecobalamin and gabapentin combination along with calcium supplements...

Best wishes

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