Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call emergency services for:
A seizure
Difficulty breathing or noisy breathing
Fainting, collapse, or inability to wake normally
Severe weakness with sudden deterioration
These emergency symptoms are not the usual course of nutritional rickets, but they require immediate assessment.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek urgent medical advice if the child develops repeated muscle cramps or spasms, marked weakness, or tingling around the mouth or limbs.
These can be signs of low calcium.
3
Does any of this apply?
Book an appointment
Arrange a routine medical appointment if a child has persistent bone pain, muscle weakness, slow growth, delayed movement skills, widened wrists or ankles, or a new change in leg shape.
The article also says
Medical review is also appropriate if a child has several risk factors for vitamin D or calcium deficiency, even when symptoms are mild.
Early changes can be difficult to recognise without an examination and blood tests.
Every sign above is quoted from the sofidex article on Nutritional rickets. If you are not sure, err upward — it is always reasonable to be checked.