Can D3 Must Be Given Along With Zincovit To An Infant?

Can 'D3 must' drops be given along with 'Zincovit' drops for our 3 month old baby.
Our doctor in chennai prescribed only Zincovit ( 5drops/day) but now my wife went to her hometown and Pediatrician in her hometown suggested to double the zincovit doze to twice along with D3 must drops , So which one we need to follow ( only Zincovit as advised by our doc in chennai or by doc in wife's hometown ) , Please advise ? Thanks