|CEGLIA, LISA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
|PITTAS, ANASTASSIOS - Tufts Medical Center
|DAWSON-HUGHES, BESS - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
Submitted to: Aging Clinical Experimental Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/22/2022
Publication Date: 1/11/2023
Citation: Ceglia, L., Pittas, A.G., Dawson-Hughes, B. 2023. Effect of vitamin D supplementation on circulating fibroblast growth factor-23 concentration in adults with prediabetes. Aging Clinical Experimental Research. https://doi.org/10.1007/s40520-022-02338-y.
Interpretive Summary: Recent reports indicate that vitamin D supplementation in high doses increases the blood level of fibroblast growth factor23 (FGF23), a compound produced largely in bone that is known to increase risk of heart disease, kidney failure, and death. We had recently completed a clinical trial to test the effect of a relatively high dose of vitamin D, 4000 IU per day, on risk of transitioning from prediabetes to type 2 diabetes. In a subset of 52 trial participants aged 70 years and older, we measured this compound in stored plasma at baseline and after 12 months in the trial. Although the blood level of 25-hydroxyvitamin D increased substantially in the supplemented group, FGF23 did not change significantly and remained no different than the placebo group. This indicates that a dose of 4000 IU of vitamin D taken daily does not increase risk of elevating the FGF23 and is therefore not expected to have adverse effects on overall chronic disease burden.
Technical Abstract: Background Recent meta-analyses report that vitamin D supplementation increases blood fibroblast growth factor-23 (FGF23) level. Objectives To determine the effect of 4000 IU/day of vitamin D3 for 12 months on circulating FGF23 levels. We also examined the association of the achieved 25-hydroxyvitamin D level [25(OH)D] with the FGF23 level at 12 months and with 12-month changes in FGF23. Methods An ancillary analysis among adults 70 years and older with prediabetes who participated in a trial comparing vitamin D3 4000 IU/day with placebo. Plasma intact FGF23 and serum 25(OH)D were measured at baseline and month 12 (M12). Results Characteristics of the 52 participants (vitamin D3 n=28; placebo n=24) did not differ significantly aside from more women than men in the vitamin D3 group. Mean+\-SD age was 73.8+\-3.7 years, BMI 31.3+\-4.2 kg/m2, and glomerular filtration rate (GFR) 76.3+\-11.8 mL/min/1.73m2 Baseline serum 25(OH)D level was 33.4+\-10.8 ng/mL and increased at M12 to 54.9+\-14.8 ng/mL in the vitamin D3 group versus 33.4+\-14.9 in the placebo (p<0.001). At baseline, GFR was inversely associated with FGF23 (r=-0.349, p=0.011). Change in FGF23 level at M12 did not differ significantly between vitamin D3 and placebo. In all participants combined, the achieved serum 25(OH)D level at M12 was not significantly associated with the M12 plasma FGF23 or the M12 change in FGF23. Conclusion In obese older adults with sufficient vitamin D status and normal renal function, vitamin D3 4000 IU/day for 12 months did not significantly alter plasma FGF23 levels.