What should I know about magnesium mangelerscheinung?

The provided context does not contain specific information about magnesium deficiency. In general, magnesium deficiency (hypomagnesemia) can cause muscle cramps, fatigue, cardiac arrhythmias, and nervousness. Causes include inadequate intake, increased loss (e.g., from diuretics, alcohol, diarrhea), or malabsorption. MyBody-X offers a nutrient deficiency test that may measure magnesium in blood – but this is not confirmed in the context. Evidence for finger-prick magnesium testing is limited; for a reliable diagnosis, consult a physician. Caveat: self-tests do not replace medical evaluation, especially for severe symptoms or pre-existing conditions.