Table 4.

Multivariable-adjusted joint/combined associationsa of supplement-only and diet-only mineral scoresb with incident colorectal cancer in the Iowa Women's Health Study (n = 35,221), 1986–2012

Supplement-only mineral score quantilesc
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HR (95% CI)HR (95% CI)HR (95% CI)HR (95% CI)HR (95% CI)
Diet-only mineralscore quantilesd
11.00 (Ref)e0.94 (0.92–0.99)0.92 (0.89–0.93)0.89 (0.84–0.92)0.87 (0.82–0.90)
20.91 (0.90–1.00)0.91 (0.84–0.88)0.86 (0.84–0.92)0.83 (0.80–0.88)0.76 (0.75–0.80)
30.89 (0.87–0.94)0.88 (0.82–0.87)0.84 (0.82–0.90)0.79 (0.77–0.83)0.73 (0.71–0.76)
40.86 (0.84–0.91)0.84 (0.81–0.87)0.83 (0.80–0.87)0.76 (0.75–0.80)0.69 (0.67–0.70)
50.84 (0.80–0.88)0.82 (0.79–0.84)0.80 (0.77–0.82)0.74 (0.72–0.77)0.66 (0.63–0.68)
  • Abbreviations: CI, confidence interval; HR, hazards ratio; Ref, reference.

  • aFrom Cox proportional hazards regression; adjusted for age, height, BMI, waist–hip ratio, smoking, physical activity, hormone replacement therapy use, education, family history, diabetes, total energy intake, total fat intake, dietary fiber intake, total fruits and vegetables intake, total red and processed meats intake, alcohol, and dietary OBS (see text).

  • bMineral scores calculated from food and supplemental intakes of calcium, copper, iodine, iron, magnesium, manganese, phosphorus, potassium, selenium, sodium, and zinc as described in the text.

  • cCategorized as took no supplemental minerals (category 1), and four categories of supplement scores among those who took supplemental minerals (categories 2–5), based on the supplement-only mineral score distribution.

  • dCategorized into five categories according to the diet-only mineral distribution.

  • eReference category: participants who took no supplemental minerals and had low diet mineral scores.