My daughter has been diagnosed with vitamin D deficiency. Do you think this is likely to make my child weaker and more susceptible to infections?
Vit. D deficiency by itself cannot be responsible solely for increased susceptibility to infections. While any vit. deficiency can potentially adversely affect the immune system and once identified should be treated appropriately it should not be viewed as an easy answer or a reason for increased rates of infection.
I would advise working with your child's pediatrician on correcting the deficiency and making sure proper work up is done should they have issues with frequent infections.