Vitamin D status, which is amenable to intervention by safely increasing sun exposure or vitamin D supplementation, was associated inversely with BP The relationship between vitamin d and blood pressure is probably driven by improved calcium uptake. In order to maximise calcium absorption from the diet vitamin d status has to at least 80nmol/l. ...

Advise him to contact a local support group for ME / CFS. also look at the various CFS/ME sites on the internet. There are no magic bullets. The younger he is and the earlier the dignosis the better chances there are for recovery.  Cognitive behaviour thereapy together with pacing are the keys for a stable individual. also a ...