Magnesium plays an important role in numerous biological
functions. Mg2+ deficiency is associated with several diseases,
e.g. Alzheimer’s disease[1], osteoporosis[2], and hypertension[
3]. Therefore, its plasma level is tightly regulated within
a narrow range (0.7-1.1 mmol/L) by intestinal absorption
and renal excretion[4]. In human intestine, fractional Mg2+
absorption varies from 11% to 65% depending on the
amount of Mg2+ intake[5]. Intestinal epithelium absorbs
Mg2+ via both saturable transcellular and non-saturable
paracellular pathways. Transcellular Mg2+ transport is an active process that requires the activity of transient receptor
potential melastatin 6 (TRPM6) and the basolateral
Na+/Mg2+ exchanger[6,7]. On the other hand, paracellular
Mg2+ transport is a passive mechanism and is implicated in
about 90% of intestinal Mg2+ absorption[7]. The paracellular
Mg2+ transport process is modulated by the tight junction
proteins, i.e. Claudin-16 and Claudin-19[8].