FOCUS is a dietary supplement and as with any dietary supplement, people should inquire about it with their physicians or medical practitioners before consuming if there is any question in regards to their health.
In regards to certain population such as lactating mothers, children, and other disorders, I do advise seeking the advice of qualified medical professional prior to using ANY dietary supplements, not just FOCUS. Even certain B vitamins can negatively affect the micronutrient balance needed to have homeostasis in some studies.