When should thyroid supplement be given- after breakfast along with other supplements including iron?

The main thing is consistency. Whether you take thyroxine (T4) before or after breakfast is your choice, but you should stick to which ever method you decide. I think the recommended method of administration is before food, but thyroxine is fairly versatile. it just means that depending on when you take it you might need slightly more or less of the hormone to achieve the same blood test results due to slightly different absorption rates.

However, do not take thyroxine with iron. Iron greatly reduces the absorption of T4 and you would most likely need to take a significantly higher T4 dose to combat this. Iron should be taken 2-3 hours or more apart from T4.

Also, vitamin C increases the absorption of T4.