Table 2. Semen quality in cases and controls by vitamin use.
| Sperm concentration (106 sperm ml−1) | Sperm number (in millions) | Semen volume (ml) | Sperm DNA fragmentation (%) | Non-motile sperm (%) | Total progressive sperm (%) | Sperm with normal morphology (%) | |
|---|---|---|---|---|---|---|---|
| Cases | |||||||
| Non-users of vitamins (n=110)a | 27.98±36.63 | 101.36±140.53 | 4.21±2.07 | 21.84±10.89 | 47.35±19.40 | 34.01±19.11 | 2.71±3.04 |
| Users of vitamins with folic acid (n=32)a | 34.22±37.31 | 129.46±145.38 | 4.77±1.90 | 21.79±13.07 | 41.23±16.21 | 37.38±18.06 | 3.23±3.52 |
| P value (adjusted for age, smoking, abstinence time)b | 0.18 | 0.069 | 0.16 | 0.49 | 0.15 | 0.42 | 0.47 |
| P value (adjusted for age, smoking, abstinence time, education)b | 0.19 | 0.081 | 0.24 | 0.48 | 0.19 | 0.50 | 0.47 |
| Controls | |||||||
| Non-users of vitamins (n=123)a | 81.93±69.39 | 333.05±109.94 | 3.59±1.47 | 12.30±7.51 | 24.85±10.21 | 59.67±12.31 | 7.65±3.68 |
| Users of vitamins with folic acid (n=34)a | 73.69±41.77 | 316.56±91.35 | 3.44±1.82 | 9.88±7.01 | 23.26±11.44 | 61.15±12.85 | 8.03±3.51 |
| P value (adjusted for age, smoking, abstinence time)b | 0.79 | 0.28 | 0.84 | 0.39 | 0.57 | 0.95 | 0.81 |
| P value (adjusted for age, smoking, abstinence time, education)b | 0.65 | 0.18 | 0.73 | 0.51 | 0.63 | 0.93 | 0.78 |
a
Values are mean±s.d.
b
Comparison between vitamin users and non-users separately for cases and controls using linear regression models with adjustment for covariates.