I have a 23 lb toddler and a 35 lb toddler. I have recently started supplementing them with 1000 IU vit d3 gummies daily. They also take Carlsons children's cod liver oil with a ratio of 225 IU vitamin A to 200 IU vitamin D3 daily. We live in Michigan and aren't getting exposure to any son lately. Before supplementing with vit d3 gummies, I thought that the daily intake of Carlsons cod liver oil and their vitamin d milk intake would suffice as enough but after researching I'm finding that may not be so. They have been coming down with colds frequently lately. My question is: Is their daily intake of 1000 IU vit d3 gummies in combination with their daily cod liver oil and milk intake too much vitamin d3 for them? What is the safe upper intake of vit d3 for toddlers?