Effect of vitamin D supplementation on glucose control in mid-late gestation: A randomized controlled trial.
Study Goal
The researchers aimed to assess the effect of vitamin D supplementation during pregnancy on glucose levels and identify factors influencing the response to vitamin D3 intake.
Results Summary
Vitamin D supplementation (1600 IU/d) stabilized fasting plasma glucose levels in pregnant women, particularly in those with specific genetic polymorphisms, higher baseline 25(OH)D levels, or metabolic conditions like GDM, overweight, or multiple pregnancies. The control group (400 IU/d) showed a significant increase in glucose levels.
Population
1720 pregnant women from three antenatal clinics in Hefei, China, at 24-28 weeks' gestation.
Effective Dosage
1600 IU/d (intervention) and 400 IU/d (control).
Duration
2 months.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
1600 IU/d vitamin D3 | no change | FPG levels | pregnant women | from 4.6 [0.4] mmol/L to 4.7 [1.1] mmol/L | had no significant variation | #1 |
400 IU/d vitamin D3 | increase | FPG levels | pregnant women | by 0.22 mmol/L (from 4.6 [0.4] mmol/L to 4.8 [1.2] mmol/L) | significantly increased | #2 |
1600 IU/d vitamin D3 | decrease | FPG levels | pregnant women | -0.2 mmol/L | difference in changes | #3 |
vitamin D supplementation | neutral | FPG variation | participants with the ApaI SNP CC genotype, or BsmI-CC, TaqI-AA, FokI-AA | - | differences in FPG variation were found | #4 |
vitamin D supplementation | decrease | FPG levels | pregnant women with basal 25(OH)D concentrations higher than 50 nmol/L | between-group difference, -0.3 mmol/L | showed the greatest decline | #5 |
vitamin D treatment | decrease | FPG | pregnant women with GDM, multiple pregnancies or who were overweight | - | more likely to have FPG decline | #6 |
vitamin D supplementation | neutral | glucose homeostasis | mid-late gestation | - | significantly protected | #7 |
BACKGROUND & AIMS: It is unclear whether vitamin D supplementation contributes to gestational glucose control and whether the specific effects vary in individuals with diverse genetic and metabolic contexts. The study aimed to assess the effect of vitamin D supplementation during pregnancy on subsequent glucose levels and to identify factors modulating the response to vitamin D3 intake. METHODS: We conducted a multicenter randomized controlled trial, 1720 pregnant women recruited from the three antenatal clinics of Hefei city, China, who were allocated to receive either 1600 IU/d vitamin D3 (n = 858) or 400 IU/d vitamin D3 (n = 862) for 2 months at 24-28 weeks' gestation. Outcomes were changes in serum 25-hydroxyvitamin D (25(OH)D) and fasting plasma glucose (FPG) levels from baseline, 32-36 weeks' gestation to delivery (37-41 weeks) quantified using a linear mixed model. RESULTS: After 2 months, FPG levels of the control group significantly increased by 0.22 mmol/L (from 4.6 [0.4] mmol/L to 4.8 [1.2] mmol/L, P < 0.001) at delivery, but that of the intervention group had no significant variation (from 4.6 [0.4] mmol/L to 4.7 [1.1] mmol/L; between-group difference in changes, -0.2 mmol/L, 95% CI, -0.3 to -0.08, P = 0.015). And differences in FPG variation were found in participants with the ApaI SNP CC genotype, or BsmI-CC, TaqI-AA, FokI-AA, respectively. Pregnant women with basal 25(OH)D concentrations higher than 50 nmol/L subgroup showed the greatest decline in FPG levels (between-group difference, -0.3 mmol/L; 95% CI, -0.5 to -0.1, P < 0.001). Moreover, pregnant women with GDM, multiple pregnancies or who were overweight were more likely to have FPG decline from vitamin D treatment. CONCLUSIONS: Vitamin D supplementation significantly protected glucose homeostasis in mid-late gestation, and glycemic response to vitamin D may be dependent on basal 25(OH)D status, VDR gene polymorphism or their metabolic profiles. TRIAL REGISTRATION NUMBER: ChiCTR2100051914. URL OF REGISTRATION: http://www.chictr.org.cn/showproj.aspx?proj=134700.