Vitamin D Stomach Virus Important Question About My 14 Month Old Son???

Important question about my 14 month old son??? - vitamin d stomach virus

My Old 14th Month had the stomach virus going around Thursday. The doctor said that juice usually last 24-48 hours and had 2 Let It continues. But the last 2 days every time my child drink milk or very bad throws or diaherra with him. He could not drink anything and everything goes well, I do not know what happened to the milk and why have these problems .. He never had any problems with the formula and has on vitamin D as milk 12 months ... what might happen?