Yes
Yes
Yes
Yes
Anything can be a symptom of something, contact a doctor if you're seriously concerned about it.
headaches, vertigo, hallucinations, confusion
Hypocalcemia
Hypocalcemia can cause depression
The prognosis for correcting hypocalcemia is excellent. However, the eye damage that may result from chronic hypocalcemia cannot be reversed.
If it's the only "symptom" you may not considere it as a red flag. It is probably the active infection symptom (or a virus infection symptom). It there is other weird symptoms (dizziness, confusion, drowsiness) and you think your child may be overdosed, you should seek medical help.
Hypocalcemia is a medical condition in which there are low serum calcium levels in the blood. It is most frequently caused by hyperparathyroidism.
Could be teething, cognitive impairment, confusion, Alzheimer's disease, etc
The disorder occurs concurrently with hypocalcemia