Magnesium deficit in a sample of the Belgian population presenting with chronic fatigue.

97 patients (25 per cent males, ages ranging from 14 to 73 years, median 38 years) with complaints of chronic fatigue (chronic fatigue syndrome, fibromyalgia or/and spasmophilia) have been enrolled in a prospective study to evaluate the Mg status and the dietary intake of Mg. An IV loading test (performed following the Ryzen protocol) showed a Mg deficit in 44 patients. After Mg supplementation in 24 patients, the loading test showed a significant decrease (p = 0.0018) in Mg retention. Mean values of serum Mg, red blood cell Mg and magnesuria showed no significant difference between patients with or without Mg deficiency. No association was found between Mg deficiency, CFS or FM. However serum Mg level was significantly lower in the patients with spasmophilia than in the other patients.