. Author manuscript; available in PMC: 2014 Aug 7.

Published in final edited form as: Health Technol Assess. 2014 Jul;18(45):1–190. doi: 10.3310/hta18450

Table 31. The effect of maternal vitamin D status in gestation on risk of bacterial vaginosis – Observational studies.

First Author and year	Bias score	Study details	Study type	Confounders/ adjustments	Number of weeks gestation when 25(OH)D was measured	Mean (SD) or median (IQR) 25(OH)D concentration (nmol/l) in cases of bacterial vaginosis	Mean (SD) or median (IQR) 25(OH)D concentration (nmol/l) in unaffected controls	Odds ratio of bacterial vaginosis from univariate analysis		Odds ratio of bacterial vaginosis from multivariate analysis		Conclusion
Bodnar, 2009 ¹⁴²	5 (low)	Pittsburgh USA Cohort=469 women all nonHispanic white or non-Hispanic black) Cases=192 (approx.)	Cohort	Presence of other sexually transmitted disease. Other confounders maternal age, parity, education, employment status, season, family income, pre-pregnant BMI, gestational age at enrolment, number of sexual partners and frequency of vaginal intercourse were not included as they did not satisfy the priori change-in-estimate criterion (>10% change in PR)	Mean (SD) 9.5 (3.2 weeks	Unadjusted geometric mean = 29.5 (27.1-32.0)	Unadjusted geometric mean = 40.1 (37.0-43.5)	Not given		Prevalence ratio (PR) given		A significant relationship observed between serum 25(OH)D and risk of bacterial vaginosis. Prevalence of bacterial vaginosis declined as 25(OH)D increased until a plateau at 80 nmol/l was reached (p<0001). At doses higher this this, no significant relationship was observed
										25(OH) conc nmol/l	Adjusted PR (95% CI)
										20 (25^th centile)	1.65 (1.01,2.69)
										50 (75^th centile)	1.26 (1.10,1.57)
										75 (90^th centile	Referent
										90 (97^th centile)	1.32 (0.84,2.09)
Hensel, 2011 ¹⁴³	4 (med)	National Health and Nutrition Examination Survey (NHANES), USA Cohort n=440 women	Cohort	Maternal age, race/ethnicity, education, poverty index, marital status, age at first sex, number of lifetime partners, ever had a female sex partner, unprotected sex in the last 30 days, current oral contraceptive use, douching frequency, active smoking, BMI	Unclear	Not given	Not given	Not given		Adjusted odd ratio (95% CI) if Vitamin D deficient (<75 nmol/l) = 2.87 (1.13,7.28). p=0.03		Serum 25(OH)D <75 nmol/l is significantly associated with an increased risk of bacterial vaginosis
Dunlop, 2011 ¹⁴⁴	2 (med)	Sample of the Nashville Birth Cohort Total cohort size=1547 women Sample size=160 women (all non-Hispanic white or non-Hispanic black) Cases=14	Cross- sectional	Race, age, smoking, BMI, gestational age at delivery, payer source	At delivery	45.0 (20.35)	60.85 (29.93)	25(OHD cone (nmol/1)	OR (95% Cl	25 (OH)D con (nmol/1)	Adjusted OR (95% Cl)	A significant risk of bacterial vaginosis seen if 25(OH)D <30 nmol/1 No significant association seen if 25(OH)D <50 nmol/1
								<30	7.58 (2.13,27.03)	<30	5.11 (1.19,21.97)
								<50	1.4 (0.79,14.93)	<50	1.2 (0.39,3.85)