I doubt he will take the water with ascorbate that little; too sour; mothers milk taste sweet. My boys detested anything than breast milk until 3 months.
Alternative is a home-made rice milk (brown organic) enriched with vit C. It has a similar taste.
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Best option in my opinion is that you take a load of vit c, and he gets his share via your milk.

About Lugols, I always took it with vitamin C, but there are other opinions out there:) Best of luck, it is a blessed time with the little ones. Also the worries, I remember!