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. Author manuscript; available in PMC: 2025 Apr 1.
Published in final edited form as: Fertil Steril. 2023 Dec 23;121(4):642–650. doi: 10.1016/j.fertnstert.2023.12.023

Association between Serum 25-hydroxyvitamin D and Antimüllerian Hormone in a Cohort of African-American Women

Anita Subramanian a, Quaker E Harmon a, Lia A Bernardi b, Mercedes R Carnethon c, Erica E Marsh d, Donna D Baird a, Anne Marie Z Jukic a
PMCID: PMC10978232  NIHMSID: NIHMS1960096  PMID: 38145700

Abstract

Objective:

To examine the association between serum 25-hydroxyvitamin D [25(OH)D] and ovarian reserve as measured by antimüllerian hormone (AMH).

Design:

Cross-sectional study.

Setting:

Detroit, Michigan area.

Subjects:

Data were obtained from a prospective cohort of self-identified Black/African-American women aged 23–35 years at the time of enrollment (N=1593), had no prior diagnosis of polycystic ovary syndrome (PCOS), were not currently pregnant, and were not missing AMH or 25(OH)D measures.

Exposure:

Serum 25(OH)D.

Main outcome measure:

Serum AMH was the main outcome. Linear regression was used to examine the associations between categorical 25(OH)D (<12 ng/mL, 12-<20, 20-<30, ≥30) and continuous natural log-transformed AMH. Associations between 25(OH)D and high (upper 10th percentile: >7.8 ng/mL) or low AMH (<0.7 ng/mL) were estimated with logistic regression. Models were adjusted for age, age-squared, BMI, hormonal contraceptive use, smoking, and exercise.

Results:

The 25(OH)D levels were low; 70% of participants were below 20 ng/mL. In fully-adjusted models, compared to 25(OH)D levels <12 ng/mL, those with 25(OH)D levels of 12-<20, 20-<30 and ≥30 ng/mL had an AMH level that was 7% (95% CI: −4, 20), 7% (95% CI: −6, 22), or 11% higher (95% CI: −7, 34), respectively. Moreover, these groups had a lower odds of having low AMH (OR[95% CI): 0.63 (0.40, 0.99), 0.60 (0.34, 1.07), 0.76 (0.35, 1.65), respectively, and the highest category of 25(OH)D had a higher odds of having high AMH, (OR [95% CI]: 1.42 [0.74, 2.72]). Exclusion of participants with either irregular cycles or very high AMH (>25 ng/mL), did not alter the associations.

Conclusion:

Taken together, these results indicate that higher levels of 25(OH)D are associated with a slightly higher AMH, a lower odds of low AMH, and a higher odds of high AMH. This evidence is weak, however, since only a small percentage of participants had high 25(OH)D. Future studies should examine populations with a wide distribution of 25(OH)D levels (both high and low), with a clinical trial design, or with longitudinal measures of both 25(OH)D and AMH.

Keywords: Ovarian reserve, vitamin D, fertility, antimüllerian hormone, reproductive health

Introduction

The role of vitamin D in calcium and phosphorus metabolism to maintain bone health is well-known (1) but there is limited research examining vitamin D in fertility and reproductive health outcomes (2, 3). Vitamin D receptors are expressed in several tissues involved with reproduction including oocytes, granulosa cells, endometrium, and placenta, suggesting a potential role of vitamin D in steroidogenesis, folliculogenesis, and implantation (3, 4). Vitamin D has been related to ovarian function and associated with markers of ovarian reserve (5–7).

Antimüllerian hormone (AMH) is a clinical marker of ovarian reserve (8). It is a dimeric glycoprotein, member of the transforming growth factor β family, and involved with growth and differentiation of tissues (8, 9). AMH is produced by the granulosa cells of pre-antral and antral follicles. It primarily functions in the regulation of early follicle development (8, 9), and inhibiting early follicular recruitment, and preventing depletion of the primordial follicle pool (8, 9). Serum AMH is affected by several environmental factors including potentially, vitamin D deficiency (10).

A vitamin D response element has been identified in the promoter region of the AMH gene, suggesting a potential role in regulating AMH expression (11). However, existing human studies on associations between vitamin D and AMH are conflicting, with a few studies reporting a positive association (12–14) while most (15–30) report a null association. The discrepant findings could be due to differences in study populations; across the literature, studies have focused on specific populations including those who were healthy (12, 13, 15–18, 30), had polycystic ovary syndrome (PCOS) (14, 19–22), or were undergoing fertility treatment (23–29). Also, sample sizes across these studies range from 72 to 848, with most studies having a smaller sample of less than 300.

Given some of the limitations of previous studies, the objective of this study was to examine the association between serum 25-hydroxyvitamin D [25(OH)D] and ovarian reserve as measured by AMH in a large community-based sample of African-American women.

Materials and Methods

Study Design

The Study of Environment, Lifestyle, and Fibroids (SELF) is a prospective cohort study designed to assess fibroid growth and development (31) and based in Detroit, Michigan. The details of study methods and participant recruitment are published elsewhere (31). In brief, participants were enrolled between 2010–2012, at which time they were 23–35 years, living in the Detroit, Michigan area, and had not had a clinical diagnosis of fibroids. Enrollment was restricted to women who selected African American or Black among a list of racial and ethnic identifiers. Participants were recruited through fliers, brochures in health clinics, television, newspaper, radio, advertisements in magazines, information booths at community events, and sending letters with details of the study to African-American women who had previously received care at the Henry Ford Health. Exclusion criteria were previous clinical diagnosis of uterine fibroids, a hysterectomy, diagnosis of a cancer requiring radiation or chemotherapy, or prior diagnosis of specific autoimmune conditions requiring medication. Enrolled participants completed a phone screening, self-administered pre-enrollment questionnaire, computer-assisted telephone interview (CATI), computer assisted web interview (CAWI), and attended a clinic visit.

SELF enrolled 1693 participants. For this cross-sectional analysis using baseline data, we excluded participants who were pregnant at baseline (N=5) or had a self-reported PCOS diagnosis (N=53). Of the 1635 remaining, one had a missing self-reported PCOS diagnosis, 34 were missing both AMH and 25(OH)D, and an additional 7 were only missing AMH, which resulted in a final analytic sample size of 1593 (Figure 1).

Figure 1:

Figure 1:

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Flow diagram of participants included in the analysis from SELF.

SELF was approved by the institutional review boards at the National Institute of Environmental Health Sciences and the Henry Ford Health in Detroit, Michigan. All participants provided written informed consent and received compensation for participation.

Measurement of 25(OH)D

Participants provided non-fasting blood samples at the enrollment visit. The samples were aliquoted and stored at −80C until laboratory measurements were performed. All samples submitted for measurement had at least one freeze thaw cycle, the freeze time for all samples was less than 2 years. Concentrations of total 25(OH)D were quantified with LIAISON a competitive chemiluminescence immunoassay (32, 33). Assays included National Institute of Standards and Technology (NIST) standards (range of concentration: 8.2 ng/mL to 24.5 ng/mL) and the measured NIST concentrations using LIAISON were similar to the expected concentrations. Quality control assays on blinded samples (SELF pooled serum; mean:15.6 ng/mL) resulted in an intra-assay coefficient of variation (CV) of 2.9% and inter-assay CV of 8.6%.

Outcome Assessment

Assessment of AMH concentrations has been previously described in detail (34). The samples were thawed once and then refrozen at −80C for long term (6–8 years) storage before performing laboratory measurements. The picoAMH assay, an enzyme linked immunosorbent assay (ELISA), was used to measure AMH (ng/mL). The lower limit of detection was 0.0013 ng/mL. The intra-assay and inter-assay coefficients of variation were <5% (35). There were two participants who had AMH values below the lower limit of detection. These two participants were assigned a value of 0.001 ng/mL using an established formula (36).

Covariates

Data on demographics, lifestyle factors, reproductive health history, hormone use, and physical activity were collected through the CATI and CAWI questionnaires. We identified covariates based on previous research (10, 37–40) and by using directed acyclic graphs (41). The covariates included age, age-squared, body mass index (BMI), hormonal contraceptive use (none, any estrogen, and only progestin) at the time of blood draw, smoking, and exercise. Height and weight were measured at the clinic visit and this information was used to calculate BMI.

Statistical Analysis

Parameterization of 25(OH)D

We fit age-adjusted linear regression models between continuous 25(OH)D and AMH to compare the following parameterizations of 25(OH)D: restricted cubic splines with 4, 5 or 6 knots and quadratic 25(OH)D (included both 25(OH)D and 25(OH)D-squared). We visually examined these results. Models fit with restricted cubic splines did not suggest evidence of non-linearity. Based on this analysis we examined 25(OH)D both linearly and in clinical categories (Supplemental Figure 1).

To account for seasonal changes in 25(OH)D, we calculated a predicted annual mean 25(OH)D using a cosinor model (42). The cosinor model is a linear model that includes the sine and cosine of the day of the year at the time of blood draw, and interactions between sine, cosine and three levels of supplement use as predictors of the natural log of 25(OH)D levels (42, 43). The intercept from this model represents the population annual mean 25(OH)D. A “residual” was calculated by taking the difference between the predicted and observed 25(OH)D for each participant. The residual was added to the model intercept and values were back transformed to the original scale to obtain a predicted annual mean 25(OH)D for each participant. The predicted annual mean 25(OH)D was used in sensitivity analysis.

We categorized measured and predicted annual mean 25(OH)D into 4 groups: <12, 12-<20, 20-<30, ≥30 ng/mL based on both the Institute of Medicine (IOM) (44) and Endocrine Society (ES) (45) guidelines. IOM defines vitamin D deficiency as <12 ng/mL, at risk of deficiency:12<20 ng/mL, and vitamin D sufficiency: ≥20 ng/mL. ES defines vitamin D sufficiency as ≥30 ng/mL.

Parameterization of AMH

Given the skewed distribution for AMH in our data, we used the natural log transformed AMH for all models. We modeled AMH both as continuous and a categorical variable. We examined AMH as a categorical variable to determine whether 25(OH)D was associated with low or high AMH levels. The categorical variable (low, normal, high) was defined based on previous literature, low AMH as levels <0.7 ng/mL (46) and high AMH as levels >7.8 ng/mL (>90th percentile) (47). Normal AMH was defined as levels between 0.7 ng/mL and 7.8 ng/mL. We used this variable in separate models and comparisons were done in pairs: low vs. normal AMH, or high vs. normal AMH. In addition, we fit a model using dichotomous AMH (low vs. not low). Since the findings from this model were similar to the one with multilevel AMH as the outcome (low, normal, high), we have not shown these results.

Parameterization of Covariates

Age was included as linear and quadratic terms due to the nonlinear association between age and AMH (48). We examined parameterization of BMI (linear and categorical) with AMH by fitting univariate linear regression models. We compared models using Akaike’s Information Criterion and determined that the best fit was using BMI as a linear term. We categorized the hormonal contraception used at the time of blood draw into 3 groups: none, any estrogen, and only progestin (43). Hormonal contraception containing estrogen included combination oral contraceptive pill, contraceptive ring or patch, and products containing only progestin included progestin only pill, hormonal implant or intrauterine device, or depot medroxyprogesterone acetate. Smoking status was categorized as none, former, <10 cigarettes/day, or ≥10 cigarettes/day. Duration of exercise (hours/week) was determined using several physical activity related questions and categorized into five groups: low, low to moderate, moderate, high, very high.

Analysis of 25(OH)D and AMH

We describe participant characteristics at enrollment, stratified by 25(OH)D, with frequencies and percentages. We used linear regression to examine the associations between 25(OH)D and continuous natural log transformed AMH. The β estimates have been presented as a percent change, which we calculated by exponentiating the β estimates for 25(OH)D, subtracting one from the number obtained, and then multiplying this number by 100. We fit two linear models: age-adjusted and fully adjusted for all covariates (age, age-squared, BMI, hormonal contraceptive use, smoking, and exercise). We used logistic regression to estimate fully adjusted odds ratios for high or low AMH. Following guidance from the American Statistical Association (49) and other experts (50, 51), we have interpreted the findings using both point estimates and confidence interval width, and did not completely base it on statistical significance.

Sensitivity Analyses

First, to account for seasonal changes in 25(OH)D, we fit the primary models using the participant-specific predicted annual mean 25(OH)D. Second, we excluded participants who had either irregular menstrual cycles (>35 days, N=63), which may represent undiagnosed PCOS leading to higher or abnormal AMH levels (52, 53), or extreme values of AMH (>25 ng/mL, N=4). Third, we added adjustment for parity because there might be differences in AMH levels between nulliparous versus parous participants (54, 55). Fourth, since AMH in this population increased from 23–25 years (48), we limited the analysis to participants between 25–35 years to further control for the non-linear association between age and AMH. Fifth, given no standardized clinical cut-point for high AMH, we fit additional models where high AMH was defined as levels >5.2 ng/mL (>75th percentile) instead of >7.8 ng/mL.

All analyses were completed using SAS software 9.4 (Cary, NC).

Results

The mean age of participants at enrollment was 29 years (standard deviation (SD): 3.4 years). The majority of participants had elevated BMIs: 21% with a BMI between 25-<30, and 59% with a BMI ≥30. Seventy eight percent had at least some post-high school education and 46% had a household income less than $20,000. Seventy three percent were non-smokers, and 66% had low to moderate levels of exercise. Almost 71% of participants were not using any hormonal methods of contraception.

The levels of 25(OH)D were low in this population with levels <12 ng/mL for 29% of participants and 12-<20 ng/mL for 41% (Table 1). An additional 22% of participants had levels of 20-<30 ng/mL; only 8% had 25(OH)D levels ≥30 ng/mL. Lower levels of 25(OH)D were observed in participants with low educational attainment, low income (<$20,000), and high BMI. Median 25(OH)D was 15.6 ng/mL (Interquartile range (IQR): 11.3–21.3 ng/mL) and median AMH level was 3.14 ng/mL (IQR: 1.68–5.22 ng/mL). AMH levels were lower among participants who were older (31–35 years) (median: 2.69 ng/mL, IQR: 1.42–4.45).

Table 1.

Characteristics of participants in SELF at enrollment visit stratified by 25(OH)D status (N=1593).

25(OH)D (ng/mL)
<12 (N=466) N (%) 12–<20 (N=648) N (%) 20–<30 (N=348) N (%) ≥ 30 (N=131) N (%)
Age (years)
 23–25 78 (16.7) 104 (16.1) 58 (16.7) 19 (14.5)
 26–28 121 (26.0) 156 (24.1) 82 (23.6) 25 (19.1)
 29–31 119 (25.5) 166 (25.6) 96 (27.6) 35 (26.7)
 31–35 148 (31.8) 222 (34.3) 112 (32.2) 52 (39.7)
Education*
 High School/ GED or Less 134 (28.8) 144 (22.3) 63 (18.1) 17 (13.0)
 Some College or Technical 242 (51.9) 335 (51.8) 176 (50.6) 41 (31.3)
 Training
 Bachelors or Graduate Degree 90 (19.3) 168 (26.0) 109 (31.3) 73 (55.7)
Household Income ($)*
 <20, 000 242 (52.2) 310 (48.3) 141 (40.6) 42 (32.1)
 20,000–50,000 170 (36.6) 222 (34.6) 141 (40.6) 44 (33.6)
 >50,000 52 (11.2) 110 (17.1) 65 (18.7) 45 (34.4)
BMI (kg/m2)
 <25 72 (15.5) 118 (18.2) 89 (25.6) 42 (32.1)
 25–29.9 82 (17.6) 137 (21.1) 85 (24.4) 32 (24.4)
 30–34.9 77 (16.5) 113 (17.4) 87 (25.0) 27 (20.6)
 35–39.9 84 (18.0) 126 (19.4) 36 (10.3) 17 (13.0)
 ≥40 151 (32.4) 154 (23.8) 51 (14.7) 13 (9.9)
Gravidity
 Never Pregnant 139 (29.8) 162 (25.0) 80 (23.0) 33 (25.2)
 Pregnant but no births 56 (12.0) 77 (11.9) 46 (13.2) 16 (12.2)
 ≥1 birth 271 (58.2) 409 (63.1) 222 (63.8) 82 (62.6)
Hormonal Contraception Use
 None 366 (78.5) 475 (73.3) 223 (64.1) 73 (55.7)
 Any Estrogen 34 (7.3) 81 (12.5) 65 (18.7) 39 (29.8)
 Progestin Only 66 (14.2) 92 (14.2) 60 (17.2) 19 (14.5)
Alcohol Intake in the Past 12 Monthsa
 None 137 (29.4) 185 (28.6) 104 (29.9) 42 (32.1)
 Moderate 217 (46.6) 329 (50.8) 193 (55.5) 70 (53.4)
 Heavy 112 (24.0) 134 (20.7) 51 (14.7) 19 (14.5)
Smoking Status
 Never 310 (66.5) 468 (72.2) 276 (79.3) 110 (84.0)
 Former 32 (6.9) 52 (8.0) 28 (8.1) 7 (5.3)
 Current
  <10 cigarettes per day 87 (18.7) 95 (14.7) 34 (9.8) 12 (9.2)
  ≥10 cigarettes per day 37 (7.9) 33 (5.1) 10 (2.9) 2 (1.5)
Duration of Exercise in a Weekb,*
 Low 83 (17.9) 105 (16.2) 44 (12.7) 20 (15.3)
 Low to Moderate 108 (23.3) 161 (24.9) 78 (22.5) 28 (21.4)
 Moderate 131 (28.2) 161 (24.9) 96 (27.8) 33 (25.2)
 High 75 (16.2) 119(18.4) 70 (20.2) 38 (29.0)
 Very High 67 (14.4) 101 (15.6) 58 (16.8) 12 (9.2)
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*

Missing: Education (N=1); Household income (N=9); Exercise (N=5).

a

Moderate: No more than 5 drinks on days when drinking or >4 drinks at a single event and no more than once/month; Heavy: ≥6 drinks/day on days when drinking or ≥4 drinks more than twice/month.

b

Low: <1 hour/week vigorous activity, 2 hours/week moderate activity, and 14 hours/week walking; Low to Moderate: MET score below 72 Moderate: MET score above 72 High: 2.5 to 5 hours/week vigorous activity or 7–10 hours/week moderate activity; Very High: 5 or more hours/week vigorous activity or 10 or more hours/week moderate activity.

BMI, Body Mass Index; 25(OH)D, 25-hydroxyvitamin D.

Linear 25(OH)D

In fully adjusted models using linear 25(OH)D, a 10 ng/mL higher 25(OH)D was associated with a 2% higher AMH level (95% CI: −3.3, 8.4). Similarly, a 10 ng/mL higher 25(OH)D was associated with 0.90 times the odds of low AMH (95% CI: 0.70, 1.16) and 1.07 times the odds of high AMH (95% CI: 0.85, 1.33)).

Categorical 25(OH)D

In models using categorical 25(OH)D, age adjusted AMH was 11% higher (95% CI: −7.4, 33.0) for participants with 25(OH)D levels ≥30 ng/mL compared with 25(OH)D levels <12 ng/mL (Table 2). Similar results were observed in fully-adjusted models. In age adjusted models, compared to 25(OH)D levels <12 ng/mL, AMH was 7.6% higher (95% CI: −3.7, 20.3) for 25(OH)D levels of 12-<20 ng/mL and 7.2% higher (95% CI: −5.8, 22.0) for 25(OH)D levels of 20-<30. Findings were similar in the fully adjusted models.

Table 2.

Association between categorical 25(OH)D and continuous AMH in women aged 23–35 years in Detroit, Michigan.

N Age-Adjusteda,b Percent Change (95% CI) (N=1593) Fully Adjusteda,b,c Percent Change (95% CI) (N=1588)
25(OH)D (ng/mL)
<12 466 Reference Reference
12–<20 648 7.6 (−3.7, 20.3) 7.5 (−3.7, 20.0)
20–<30 348 7.2 (−5.8, 22.0) 6.6 (−6.5, 21.6)
≥30 131 11.0 (−7.4, 33.0) 11.2 (−7.4, 33.7)
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a

AMH is natural log transformed and continuous.

b

Linear regression models were used to estimate associations between 25(OH)D and AMH.

The β estimates have been presented as a percent change.

c

Adjusted for age, age-squared, BMI, hormonal contraceptive use, smoking and exercise. Missing exercise, N=5. For 25(OH)D: <12, N=464; 12–<20, N=647; 20–<30 N=346; ≥30, N=131.

AMH, Antimullerian Hormone; 25(OH)D, 25-hydroxyvitamin D.

Association between Categorical 25(OH)D and Categorical AMH

In models of 25(OH)D and low or high AMH compared to normal AMH, the estimates observed were generally in the hypothesized direction, i.e., there was a tendency for high 25(OH)D to be associated with high AMH (Table 3). In fully adjusted models compared to 25(OH)D levels <12 ng/mL, high levels of 25(OH)D were associated with higher odds of having high AMH (25(OH)D: ≥30 ng/mL, aOR [95% CI]: 1.42 [0.74, 2.72]). Compared to 25(OH)D levels <12 ng/mL, there was a lower odds of having low AMH for 25(OH)D levels ≥12 ng/ml, suggesting that participants with 25(OH)D levels <12 ng/mL had the highest frequency of having low AMH.

Table 3.

Associations between 25(OH)D and low or high levels of AMH.

AMH (ng/mL)
Low (<0.7 ng/mL) (N=116) High (>7.8 ng/mL) (N=154)
N Age-Adjusteda OR (95% CI) Fully Adjusteda,b OR (95% CI) N Age-Adjusteda OR (95% CI) Fully Adjusteda,b OR (95% CI)
25(OH)D (ng/mL)
<12 44 Reference Reference 46 Reference Reference
12–<20 41 0.62 (0.40, 0.98) 0.63 (0.40, 0.99) 62 0.95 (0.63, 1.42) 0.93 (0.61, 1.41)
20–<30 21 0.59 (0.34, 1.02) 0.60 (0.34, 1.07) 30 0.83 (0.51, 1.35) 0.82 (0.49, 1.37)
≥30 10 0.71 (0.34, 1.46) 0.76 (0.35, 1.65) 16 1.33 (0.72, 2.46) 1.42 (0.74, 2.72)
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a

Logistic regression models were used to estimate adjusted odds ratio for high or low AMH. The categorical variable for AMH was used in separate models and comparisons were done in pairs: low vs. normal, or high vs. normal. Low AMH was defined as <0.7 ng/mL based on previous literature (46); normal (0.7–7.8 ng/mL); high AMH (>90th percentile: >7.8 ng.ml) (47).

b

Adjusted for age, age-squared, BMI, hormonal contraceptive use, smoking, exercise.

AMH, Antimullerian Hormone; 25(OH)D, 25-hydroxyvitamin D.

Sensitivity analyses.

Models fit with the predicted annual mean 25(OH)D showed associations in the same directions and similar magnitude as the measured values (Supplemental Table 1 and Supplemental Table 2). Models that excluded participants with either irregular cycles or extreme values of AMH, adjusted for parity, or limited to participants aged 25–35 yielded results similar to the primary results (Supplemental Table 3 and Supplemental Table 4). When we fit models using a different cut-point for high AMH (>5.2 ng/mL), the estimate for high 25(OH)D was attenuated (aOR [95% CI]: 1.17 [0.72, 1.89] compared to aOR of 1.42 in primary analysis).

Discussion

In this cross-sectional study of African American participants living in the Detroit, Michigan area, we observed that a 10ng/ml increase in 25(OH)D, which would approximate an increase from deficiency to sufficiency, was associated with a small, 2% increase in AMH. In addition, a higher level of 25(OH)D, at least 30 ng/ml, was associated with both a reduced odds of having low AMH (a proxy for DOR), and an increased odds of having high AMH. While all of the confidence intervals for these estimates are imprecise, which indicates an important degree of uncertainty, all of the estimates are consistent in the direction of the association: higher 25(OH)D was associated with higher AMH.

When we excluded those with either irregular cycles or extreme values of AMH in our sensitivity analyses to determine if the association we observed was driven by underlying, undiagnosed PCOS, our results were similar. A major limitation of our data is the few participants with higher levels of 25(OH)D. Only ~8% had 25(OH)D ≥30 ng/mL and <2% with 25(OH)D levels ≥40 ng/mL. Studies indicate that levels of 25(OH)D ≥40 ng/mL may be important for other reproductive outcomes such as menstrual cycle length (56), fecundability (57), pregnancy outcomes (among PCOS women undergoing fertility treatment) (58), and preterm birth (59).

Prior studies in the existing literature have reported mixed and conflicting findings. Eighteen observational studies have previously examined the association between 25(OH)D and AMH (12–29). Of the studies focusing on 25(OH)D and AMH, five studies included women with PCOS (14, 19–22) and eight studies examined this association among infertile women (23–29) or those with primary ovarian insufficiency (60). A recent systematic review and meta-analysis which combined studies with participants who were healthy or had either PCOS or infertility (3406 participants) reported no correlation between 25(OH)D and AMH (Fisher’s Z: −0.03, 95% CI: −0.11, 0.04) (6). Among the five studies which reported on healthy ovulatory women, three studies did not observe an association between 25(OH)D and AMH (15–17). One of these was a cross-sectional study of Korean women which was limited with a small sample size (N=73) and only reported the correlation coefficient between 25(OH)D and AMH, which makes it hard to interpret the association (15). Another study of 291 Korean women only included older women of reproductive age (35–49 years) (16). The third reported on 656 participants in the Nurses’ Health Study II, but few participants had 25(OH)D levels less than 20 ng/mL which does not allow for adequate comparison of high vs low 25(OH)D (17).

In contrast, there are 3 studies that reported some increase in AMH with higher 25(OH)D. A cross-sectional study in the United States (N=388) reported a positive correlation between 25(OH)D and AMH among women of late reproductive age (≥40 years), but no associations were observed for women <35 years or 35–39 years (12). A prospective time-to-pregnancy study in the United States (N=561) reported that insufficient 25(OH)D (<30 ng/mL) was associated with an increased odds of low AMH (OR [95% CI]: 1.8 [0.91, 3.6]) but the prevalence of low 25(OH)D was small (13). In a meta-analysis of three small intervention studies, one of which included infertile women, vitamin D supplementation significantly increased AMH levels (N=81, SMD: 0.49, 95% CI: 0.17, 0.80) (61).

However, our study has limitations. The cross-sectional design does not account for life-course changes in 25(OH)D. In addition, vitamin D levels are affected by season. However the seasonal change in vitamin D in this study population was small (62) and the results did not substantially change when we adjusted for season. A major limitation was that we did not have a wide distribution of 25(OH)D (70% of participants had levels below 20 ng/mL and only ~8% had 25(OH)D levels ≥30 ng/mL) which limits the power to detect associations between higher 25(OH)D and AMH. In addition, we may not have adequately accounted for PCOS (often accompanied by higher AMH levels) though we excluded participants with a self-reported diagnosis of PCOS. However, when we excluded women either with irregular cycles or those with extremely high AMH levels which might indicate undiagnosed PCOS, the findings were essentially unchanged.

The strengths of our study include the large sample size of community-recruited participants. To our knowledge, this current study had the largest sample size to date in this literature. Our unique study population of African-American participants and those without PCOS or infertility, distinguishes it from other studies in the literature. Although our study was limited to an African-American population who tend to have lower 25(OH)D levels (63), the broad community-based methods used for recruitment helps with generalizability. The mean 25(OH)D observed in our study are comparable to other studies which reported lower 25(OH)D levels in U.S. Non-Hispanic Black populations (64, 65), suggesting that with respect to 25(OH)D levels alone, our population is representative of U.S. non-Hispanic Black females.

In conclusion, higher levels of 25(OH)D are associated with a slightly higher AMH, a lower odds of low AMH, and a higher odds of high AMH in this cross-sectional study of African-American participants aged 23–35. To address the limitations of the current work, and prior studies in the literature, future work should examine this association in large studies with a wide distribution of 25(OH)D levels (both low and high) with longitudinal measures of both 25(OH)D and AMH measured among women from the general population who represent the entire reproductive lifespan. In addition, we believe that this study and the proposed future studies might guide the design of randomized controlled trials to administer vitamin D supplements to target and maintain 25(OH)D levels of at least 30 ng/mL to allow evaluation of higher levels of 25(OH)D and AMH

Supplementary Material

1

Attestation Statements:

  • Data regarding any of the subjects in the study has not been previously published unless specified.

  • Data will be made available to the editors of the journal for review or query upon request.

Capsule:

Higher levels of 25(OH)D are associated with higher AMH in this cross-sectional study of African-American participants aged 23–35 years.

Acknowledgements

We would like to thank Drs. Natalie Shaw, M.D., MMSc. and Christine Langton, Ph.D. for providing feedback on drafts of this manuscript.

Funding Statement:

This research was supported by the Intramural Research Program of the National Institutes of Health, National Institute of Environmental Health Sciences (Z01ES103333, ZIAE049013), and, in part, by funds allocated for health research by the American Recovery and Reinvestment Act. Measurement of vitamin D levels in baseline samples was funded by the NIH Office of Disease Prevention. AMH measurement was funded by the National Institutes of Health (R01HD088638; to E.E.M).

Footnotes

Disclosure Statement:

A.S. has nothing to disclose. Q.E.H. has nothing to disclose. L.A.B. has nothing to disclose. M.R.C. has nothing to disclose. E.E.M is a consultant for Alnylam and Myovant Sciences. D.D.B. has nothing to disclose. A.M.Z.J. has nothing to disclose.

Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Data Sharing Statement:

Data described in the manuscript, code book, and analytic code will be made available upon reasonable request to Dr. Anne Marie Z. Jukic, but participant consent limits full data sharing.

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Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

1
NIHMS1960096-supplement-1.docx (47.4KB, docx)

Data Availability Statement

Data described in the manuscript, code book, and analytic code will be made available upon reasonable request to Dr. Anne Marie Z. Jukic, but participant consent limits full data sharing.

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