TABLE 1.
Selected characteristics by total folate intake among participants with ≥2 y of follow-up in the Women's Health Initiative Observational Study1
| Total folate intake (DFE) |
||||||||
| <242 |
242 to <542 |
542 to <939 |
≥939 |
|||||
| Characteristic | n | Value | n | Value | n | Value | n | Value |
| Age (y) | 21,667 | 62.9 ± 7.52 | 21,696 | 63.4 ± 7.4 | 21,726 | 63.6 ± 7.4 | 21,731 | 64.2 ± 7.1 |
| BMI (%) | ||||||||
| <25 kg/m2 | 8202 | 38.3 | 8431 | 39.3 | 9319 | 43.4 | 9509 | 44.2 |
| 25 to <30 kg/m2 | 7377 | 34.5 | 7383 | 34.4 | 7317 | 34.1 | 7288 | 33.9 |
| 30 to <35 kg/m2 | 3707 | 17.3 | 3478 | 16.2 | 3184 | 14.8 | 3091 | 14.4 |
| ≥35 kg/m2 | 2120 | 9.9 | 2143 | 10.0 | 1653 | 7.7 | 1610 | 7.5 |
| Race-ethnicity (%) | ||||||||
| White | 17,260 | 79.7 | 18,087 | 83.4 | 18,836 | 86.7 | 19,315 | 88.9 |
| Black | 2273 | 10.5 | 1802 | 8.3 | 1218 | 5.6 | 1025 | 4.7 |
| Other | 2134 | 9.8 | 1807 | 8.3 | 1672 | 7.7 | 1391 | 6.4 |
| Family income (%) | ||||||||
| <$20,000 | 3847 | 19.2 | 3065 | 15.3 | 2829 | 13.9 | 2487 | 12.3 |
| $20,000–$34,999 | 4799 | 24.0 | 4624 | 23.1 | 4790 | 23.6 | 4521 | 22.3 |
| $35,000–$49,999 | 3893 | 19.4 | 4049 | 20.2 | 4093 | 20.2 | 4289 | 21.2 |
| $50,000–$74,999 | 3777 | 18.9 | 4020 | 20.1 | 4285 | 21.1 | 4418 | 21.8 |
| ≥$75,000 | 3701 | 18.5 | 4277 | 21.3 | 4297 | 21.2 | 4554 | 22.5 |
| No. of relatives with CRC (%) | ||||||||
| None | 16,460 | 84.4 | 16,514 | 83.8 | 16,670 | 84.4 | 16,551 | 83.9 |
| 1 | 2713 | 13.9 | 2840 | 14.4 | 2762 | 14.0 | 2832 | 14.4 |
| ≥2 | 338 | 1.7 | 352 | 1.8 | 314 | 1.6 | 346 | 1.8 |
| History of colonoscopy (%) | ||||||||
| No | 10,618 | 50.1 | 10,086 | 47.2 | 9606 | 44.8 | 8617 | 40.0 |
| Yes | 10,567 | 49.9 | 11,285 | 52.8 | 11,850 | 55.2 | 12,917 | 60.0 |
| Smoking status (%) | ||||||||
| Never | 10,782 | 50.5 | 11,025 | 51.5 | 10,871 | 50.7 | 10,903 | 50.8 |
| Past | 8774 | 41.1 | 9090 | 42.5 | 9330 | 43.5 | 9648 | 45.0 |
| Current | 1794 | 8.4 | 1273 | 6.0 | 1231 | 5.7 | 893 | 4.2 |
| Pack-years of smoking (%) | ||||||||
| Never-smoker | 10,782 | 51.6 | 11,025 | 52.8 | 10,871 | 51.9 | 10,903 | 52.1 |
| <5 | 2994 | 14.3 | 3100 | 14.8 | 3136 | 15.0 | 3199 | 15.3 |
| 5 to <20 | 2957 | 14.1 | 3062 | 14.7 | 2993 | 14.3 | 3016 | 14.4 |
| ≥20 | 4170 | 19.9 | 3713 | 17.8 | 3941 | 18.8 | 3803 | 18.2 |
| Dietary alcohol intake (g) | 21,667 | 4.9 ± 10.8 | 21,696 | 5.7± 11.9 | 21,726 | 5.4 ± 10.9 | 21,731 | 5.7 ± 11.6 |
| Alcohol use (%) | ||||||||
| Nondrinker | 2738 | 12.7 | 2408 | 11.2 | 2146 | 9.9 | 1993 | 9.2 |
| Past drinker | 4295 | 20.0 | 3802 | 17.6 | 3753 | 17.4 | 3879 | 17.9 |
| <1 drink/mo | 2590 | 12.0 | 2455 | 11.4 | 2550 | 11.8 | 2302 | 10.6 |
| <1 drink/wk | 4220 | 19.6 | 4211 | 19.5 | 4485 | 20.8 | 4452 | 20.6 |
| 1 to <7 drinks/wk | 5097 | 23.7 | 5752 | 26.7 | 5872 | 27.2 | 6000 | 27.8 |
| ≥7 drinks/wk | 2574 | 12.0 | 2922 | 13.6 | 2803 | 13.0 | 2991 | 13.8 |
| Physical activity (MET-h/wk) | 21,293 | 11.4 ± 13.2 | 21,433 | 14.2 ± 14.5 | 21,542 | 13.8 ± 14.1 | 21,589 | 16.1 ± 15.2 |
| Postmenopausal hormone use (%) | ||||||||
| None | 9484 | 43.8 | 9521 | 43.9 | 7940 | 36.6 | 7621 | 35.1 |
| Past | 3147 | 14.5 | 3121 | 14.4 | 3313 | 15.3 | 3349 | 15.4 |
| Current estrogen | 5059 | 23.4 | 5141 | 23.7 | 5730 | 26.4 | 5829 | 26.8 |
| Current estrogen + progesterone | 3951 | 18.3 | 3888 | 17.9 | 4725 | 21.8 | 4919 | 22.6 |
| NSAID use (%) | ||||||||
| No | 15,026 | 69.3 | 14,736 | 67.9 | 13,672 | 62.9 | 13,171 | 60.6 |
| Yes | 6641 | 30.7 | 6960 | 32.1 | 8054 | 37.1 | 8559 | 39.4 |
| Multivitamin supplement use (%) | ||||||||
| No | 21,620 | 99.8 | 20,494 | 94.5 | 5194 | 23.9 | 2984 | 13.7 |
| Yes | 47 | 0.2 | 1202 | 5.5 | 16,532 | 76.1 | 18,747 | 86.3 |
| Red meat intake (medium portions/d) | 21,667 | 0.6 ± 0.5 | 21,696 | 0.7 ± 0.6 | 21,726 | 0.6 ± 0.5 | 21,731 | 0.6 ± 0.5 |
| Total energy intake (kcal) | 21,667 | 1295 ± 441 | 21,696 | 1762 ± 614 | 21,726 | 1454 ± 551 | 21,731 | 1773 ± 621 |
| Dietary folate intake (DFE) | 21,667 | 175.3 ± 43.8 | 21,696 | 324.4 ± 82.1 | 21,726 | 261.2 ± 167.0 | 21,731 | 400.6 ± 189.2 |
| Supplemental folic acid intake (μg) | 21,667 | 0.2 ± 3.3 | 21,696 | 10.3 ± 36.5 | 21,726 | 331.9 ± 135.9 | 21,731 | 481.6 ± 285.6 |
| Folate, total intake (DFE) | 21,667 | 175.7 ± 42.7 | 21,696 | 341.9 ± 79.5 | 21,726 | 825.5 ± 102.6 | 21,731 | 1219.3 ± 477.6 |
| Dietary vitamin B-12 intake (μg) | 21,667 | 4.7 ± 2.6 | 21,696 | 6.5 ± 3.7 | 21,726 | 5.4 ± 3.3 | 21,731 | 6.6 ± 4.0 |
| Supplemental vitamin B-12 intake (μg) | 21,667 | 7.6 ± 59.4 | 21,696 | 9.7 ± 61.2 | 21,726 | 20.2 ± 76.3 | 21,731 | 32.9 ± 99.0 |
| Vitamin B-12 intake, total (μg) | 21,667 | 12.3 ± 59.4 | 21,696 | 16.2 ± 61.2 | 21,726 | 25.5 ± 76.3 | 21,731 | 39.5 ± 98.9 |
| Dietary vitamin B-6 intake (mg) | 21,667 | 1.3 ± 0.5 | 21,696 | 1.8 ± 0.7 | 21,726 | 1.5 ± 0.6 | 21,731 | 1.9 ± 0.7 |
| Supplemental vitamin B-6 intake (mg) | 21,667 | 2.8 ± 22.7 | 21,696 | 4.9 ± 35.3 | 21,726 | 7.8 ± 31.6 | 21,731 | 14.6 ± 41.8 |
| Vitamin B-6 intake, total (mg) | 21,667 | 4.1 ± 22.7 | 21,696 | 6.7 ± 35.3 | 21,726 | 9.3 ± 31.6 | 21,731 | 16.5 ± 41.8 |
| Dietary riboflavin intake (mg) | 21,667 | 1.6 ± 0.6 | 21,696 | 2.2 ± 0.9 | 21,726 | 1.8 ± 0.8 | 21,731 | 2.3 ± 0.9 |
| Supplemental riboflavin intake (mg) | 21,667 | 1.2 ± 15.5 | 21,696 | 2.2 ± 16.7 | 21,726 | 4.8 ± 16.5 | 21,731 | 10.5 ± 28.0 |
| Riboflavin intake, total (mg) | 21,667 | 2.7 ± 15.5 | 21,696 | 4.5 ± 16.7 | 21,726 | 6.6 ± 16.5 | 21,731 | 12.8 ± 27.9 |
1
Values do not add up to 100% because of missing values and rounding; numbers are frequencies and percentages unless otherwise noted. CRC, colorectal cancer; DFE, dietary folate equivalent; MET-h, metabolic equivalent task hours; NSAID, nonsteroidal antiinflammatory drug.
2
Mean ± SD (all such values).