We get asked a lot about supplements for milk allergy. Not only do parents wonder if they need to supplement, but they wonder what brands are allergy-safe.
My boys drink unsweetened almond milk with 50% more calcium than milk, and I've been adding a Vitamin D drop to it. My chiro friend tells me that vitamin D is important for calcium absorption.
Carlson is the brand we use, and they have Vitamin D for both babies and kids. The drops are tasteless and easy to use. We get ours on Amazon.