Serum Magnesium Concentrations in the United States-An Updated Population Reference Interval in Children and Adults.
Level 4 - case-series / case-control
Cross-sectional survey of a representative population sample (NHANES 2021-2023).
PubMed 42000046 · doi:10.1016/j.tjnut.2026.101539
What was done
Researchers analyzed cross-sectional data from 6,261 nonpregnant and nonlactating civilian participants (787 children aged 12-18 years and 5,474 adults aged 19 years and older) in the 2021-2023 National Health and Nutrition Examination Survey (NHANES). Reference intervals were calculated according to International Federation of Clinical Chemistry guidelines. Linear regression was used to compare serum magnesium levels across sex, age, and metabolic health status (total population, metabolically healthy, hypertension, diabetes, and chronic kidney disease).
What was found
In children (total population), reference intervals were 1.70-2.19 mg/dL (0.70-0.90 mmol/L) for boys and 1.64-2.18 mg/dL (0.68-0.90 mmol/L) for girls, with girls having significantly lower mean levels (P = 0.003). In metabolically healthy adults, reference intervals were 1.72-2.26 mg/dL (0.71-0.93 mmol/L) for males and 1.70-2.21 mg/dL (0.70-0.91 mmol/L) for females (P < 0.001 for sex difference). Adult males and females with diabetes (P < 0.001 for both), hypertension (P = 0.012 for males; P = 0.029 for females), or chronic kidney disease (P = 0.007 for males; P = 0.002 for females) had significantly lower mean serum magnesium compared to metabolically healthy counterparts. An estimated 67.8% of US adults met the threshold for chronic latent magnesium deficiency (<2.06 mg/dL or <0.85 mmol/L).
Why it matters
This study provides the first updated US population-based serum magnesium reference intervals in roughly 50 years, replacing 1971-1974 NHANES I baselines. The high prevalence of sub-optimal serum magnesium highlights widespread potential deficiency among US adults, particularly those with metabolic disorders.
Limits
The study is cross-sectional and cannot establish causal relationships between metabolic conditions and lower magnesium levels. Serum magnesium represents less than 1% of total body magnesium and is tightly homeostatically controlled, which may obscure intracellular or bone tissue depletion. The sample excluded children under 12 years of age, pregnant or lactating individuals, and institutionalized populations.
Cited by
- context Most people are deficient in magnesium.