Do you know what antibiotics your husband took?

Some of them cause neuropathy. Flagyl and fluoroquinolones like Cipro, Levaquin and Avelox cause PN.

Does he use a statin for cholesterol control?

I do not see papers on PubMed linking lisinopril to PN. In fact there are papers that show the reverse, that PN improves with lisinopril. Many are animal studies but there are some on humans with diabetic neuropathy.

Supplements like B12 and Vit D can be tested for before starting with them. That would give you an idea if you need them at all. People who are not deficient typically do not respond to them when taken extra.