Perspective: US Adult Magnesium Requirements Need Updating: Impacts of Rising Body Weights and Data-Derived Variance.

ABSTRACT

Adequate magnesium intakes are associated with lower diabetes, hypertension, and cardiovascular disease (CVD) risk but are low in modern diets. Magnesium DRIs, estimated using standard reference body weights (SRBWs) lower than current mean US adult body weights (BWs), need revision. Magnesium DRIs assume variance at 10% CV, whereas balance study data suggests 20-30% CV. Here, estimated average requirements (EARs), the DRI measure estimating average magnesium requirements for healthy adults, were corrected using 2011-2014 mean US adult BWs. Magnesium EARs (in mg magnesium/d) increased 17% for men (330-350 to 386-409) and 25% for women (255-265 to 319-332). RDAs, the DRI measure meant to cover the magnesium needs of 98% of healthy adults, were calculated using BW-corrected EARs given 3 CV levels 1) 10% (assumed in 1997 DRIs), 2) 20% (model-derived variance from USDA magnesium studies), and 3) 30% (using USDA plus older human magnesium balance data). BW-corrected magnesium RDAs (in mg magnesium/d) rose from 400-420 and 310-320 for men and women, respectively, to 1) 463-491 and 383-398 (16.5% and 23.5% increases), 2) 540-573 and 447-465 (35.5% and 44.5% increases), and 3) 617-654 and 511-531 (55% and 65.5% increases). These recalculations move magnesium intakes estimated to prevent disease into ranges found in traditional diets and to intake levels shown to lower hypertension, diabetes, and CVD risk. In conclusion, mean BW rises over the last ≥20 y and data-driven estimates of CV indicate that reliable US adult magnesium RDAs are ≥60-235 and 70-210 mg magnesium/d higher for men and women, respectively, than the current 1997 RDAs. US adult BMIs are <25 kg/m2 when calculated with SRBWs but >25 with actual mean BWs. Adjustments for rising BW are necessary for magnesium DRIs to remain useful tools for defining magnesium intake adequacy/deficiency.