TABLE 1.

General characteristics of the study participants (n = 2592)¹

Characteristic	Distribution
β-Carotene (μg/d)
Total, diet plus supplement	1931 ± 99.42
Diet only	1931 ± 99.4
Vitamin C (mg/d)
Total, diet plus supplement	212 ± 11.1
Diet only	90.9 ± 3.4
Vitamin E (mg/d)
Total, diet plus supplement	49.2 ± 4.23
Diet only	3.69 ± 0.17
AC1 (nutritional score)3
Total, diet plus supplement	98.6 ± 1.51
Diet only	96.6 ± 1.62
AC2 (nutritional score)4
Total, diet plus supplement	150 ± 2.23
Diet only	145 ± 2.28
Magnesium (mg/d)
Total, diet plus supplement	331 ± 4.85
Diet only	286 ± 3.87
Speech-frequency PTA (dB)5	12.7 ± 0.35
High-frequency PTA (dB)6	18.8 ± 0.59
Hearing loss (%)	11.77
Age (y)	42.1 ± 0.33
BMI (kg/m2)	28.0 ± 0.14
Noise exposures
Occupational noise8 (O*NET score)	3.1 ± 0.02
Recreational noise (exposed %)	27.5
Firearm noise (exposed %)	7.8
Sex (male %)	47.8
Race ethnicity (%)
Non-Hispanic white	73.0
Non-Hispanic black	11.2
Mexican American	6.8
Other	9.0
Ototoxic medication (current use %)	14.3
Cumulative cigarette pack-years (%)
Never	54.4
<20	33.2
≥20	12.4
Current hypertension (%)	23.5
Current diabetes mellitus (%)	4.5

¹Participants included individuals with all variables of interest: hearing thresholds, nutrient intake, age, BMI, sex, race-ethnicity, ototoxic medication use, cumulative cigarette pack-years, hypertension, diabetes, and occupational, recreational, and firearm noise. AC1, antioxidant composite 1; AC2, antioxidant composite 2; O*NET, Occupational Network; PTA, pure-tone average.

²Four-year weighted mean ± SE (all such values).

³β-Carotene + vitamin C (0 < nutritional score < 200).

⁴β-Carotene + vitamin C + vitamin E (0 < nutritional score < 300).

⁵At 0.5, 1, 2, and 4 kHz.

⁶At 3, 4, and 6 kHz.

⁷Weighted percentages (all such values).

⁸1 < O*NET noise scale < 5.