Table 1—

Baseline characteristics among 38,025 women according to quintiles of total magnesium intake in the WHS

VariableQuintile of magnesium intake (mg/day)
1 (lowest)2345 (highest)
Median intake (mg/day)255296328365433
Age (years)52.5 ± 6.553.3 ± 6.853.9 ± 6.954.4 ± 7.155.3 ± 7.4
Smoking (%)
 Current17.414.513.010.79.4
 Never52.351.049.751.251.1
 Past30.334.537.338.039.5
Exercise (%)
 Rarely/never51.041.235.833.028.7
 <1/week20.822.521.218.516.6
 1–3/week22.529.032.735.737.3
 ≥4/week5.77.410.312.817.5
Alcohol consumption (%)
 Rarely/never49.443.241.141.045.3
 1–3 drinks/month13.112.912.913.713.5
 1–6 drinks/week27.432.734.834.532.0
 ≥1 drink/day10.111.211.210.89.2
Postmenopausal (%)48.651.254.557.361.0
Postmenopausal hormone use (%)
 Never53.650.747.645.241.2
 Past10.19.49.710.510.7
 Current36.339.842.644.248.2
Mean BMI (kg/m2)26.626.225.825.525.2
Multivitamin use (%)17.320.523.531.154.3
Magnesium supplement (%)2.35.28.918.854.8
History of hypertension (%)*27.825.224.324.123.8
History of high cholesterol (%)*25.225.326.427.329.0
Parental history of diabetes (%)*25.524.824.724.024.6
Total energy (kcal)1,682 ± 5561,737 ± 5261,764 ± 5311,765 ± 5271,683 ± 521
Carbohydrate (g)210 ± 36.6214 ± 31.1220 ± 30.3228 ± 31.6238 ± 35.1
Total fat (g)64.5 ± 11.760.9 ± 10.257.8 ± 9.954.3 ± 10.350.6 ± 11.3
Cholesterol (mg)240 ± 75.1234 ± 68.1228 ± 65.3218 ± 66.8205 ± 74.7
Proteins (g)74.7 ± 13.879.6 ± 12.782.2 ± 13.183.8 ± 13.885.1 ± 15.4
Fiber (g)14.1 ± 3.416.9 ± 3.518.7 ± 3.920.9 ± 4.724.3 ± 7.4
Dietary GI77.7 ± 4.575.8 ± 4.174.8 ± 4.174.1 ± 4.473.3 ± 4.8
  • Data are mean ± SD, unless otherwise indicated. All covariate values are according to the quintiles of total magnesium intake. All the means of nutrients are energy adjusted.

  • *

    * History of hypertension is defined as a diagnosis by physician or self-reported blood pressure >140/90 mmHg, and history of high cholesterol and family history of diabetes were self-reported.

  • Dietary GI is defined as glycemic index, an indicator of blood glucose induced by a specified food, which compares the plasma glucose response to this food with the response induced by the same amount of a carbohydrate source, in this case, white bread.