The presenter is suggesting that low melatonin production is a key contributor to the development of scoliosis. Specifically, that serotonin needs to efficiently convert to melatonin. That, to me, implies that you have to have adequate levels of serotonin in order for the efficient conversion to melatonin to take place.
What if the suffer also has frequent migraines? Well, as this paper says, "... all migraine suffers should be treated with magnesium". Why? As this page describes, migraines seem to be related to low serotonin levels. And magnesium is a key compound in the conversion of tryptophan to serotonin.
So could it be that a key treatment for someone suffering scoliosis and migraines is magnesium? Perhaps with the addition of tryptophan (say, in the form of a mature brie).
We've started treating our scoliotic migraine family member with magnesium oil. Touch wood, he's not suffered a migraine since. Will this help his scoliosis? I don't know, but it's a fascinating line of enquiry and far more appealing than the thought of braces or spinal surgery.