Table 1 Characteristics of premenstrual syndrome cases and controls at the time of blood collection, NHS2 PMS Sub-study

Mean (SD)

Mean (SD)

Age (years)

40.6 (4.0)

40.7 (3.8)

0.94

Body mass index (kg/m²)

25.7 (5.8)

25.4 (5.8)

0.50

Body mass index at age 18 (kg/m²)

21.5 (3.4)

21.4 (3.5)

0.81

Age at menarche (years)

12.5 (1.4)

12.4 (1.5)

0.45

Number of full term pregnancies

2.0 (1.2)

2.0 (1.3)

0.43

Age at first birth (years)*

26.2 (4.2)

26.7 (4.1)

0.11

Physical activity (MET/wk)

18.7 (19.4)

20.0 (20.8)

0.36

Alcohol intake (grams/day)

4.6 (6.8)

3.7 (6.5)

0.05

%

%

White race

96.0

98.8

0.02

Mother had > high school education

31.9

39.9

0.02

More than 5 moles on lower leg†

15.5

17.0

0.57

Low UV radiation index region of US

22.2

26.0

0.22

Current smoker

11.2

4.7

<0.001

Former smoker

30.7

15.7

<0.001

Tubal ligation

31.1

25.2

0.06

Significant childhood trauma

18.1

5.6

<0.001

Antidepressant use&

14.7

6.2

<0.001

Ever used oral contraceptives

86.5

77.3

<0.001

Calcium/vitamin D supplement use

41.4

39.9

0.67

B vitamin supplement use

17.7

10.0

0.002

Regular multivitamin use

48.9

44.1

0.18

Biomarkers

Mean (SD)

Mean (SD)

25-hydroxyvitamin D (nmol/L)

66.5 (20.5)

64.8 (19.9)

0.24

Total calcium (mg/dL)

9.74 (0.39)

9.72 (0.38)

0.64

Intact Parathyroid hormone (pg/mL)

31.2 (11.5)

31.1 (11.6)

0.92