In recent kidney transplant recipients (KTRs), cholecalciferol supplementation may improve vitamin D deficiency, tertiary hyperparathyroidism (THPT), and coronary calcification.
In a retrospective of 209 KTRs, 96.3% had hyperparathyroidism prior to surgery and 94.3% had persistent hyperparathyroidism at 2 weeks after surgery. Parathyroid hormone (PTH) levels decreased from 449.5 pg/mL at baseline to 192.5 pg/mL at 2 weeks. Fibroblast growth factor 23 (FGF23) levels also decreased after surgery but remained abnormally elevated at 623.8 pg/mL at 2 weeks. Klotho levels were suboptimal at 392 pg/mL at 2 weeks.
At 2 weeks, 108 of the 209 KTRs had vitamin D deficiency, defined as 25-hydroxycholecalciferol (25[OH]D) levels less than 75 nmol/L, and were treated with 2000 IU cholecalciferol daily.
At 12 months, treated KTRs had more favorable lab parameters than untreated KTRs, Yun-Ying Shi, MD, of Sichuan University in China, and colleagues reported in Endocrine Connections. Significantly lower proportions of the treatment group still had vitamin D deficiency (9.2% vs 67.3%) and persistent hyperparathyroidism (17.6% vs 88.1%) along with hypercalcemia (11.1% vs 71.3%). Levels of PTH (50.8 vs 165.8 pg/mL) and FGF23 (30.3 vs 87.0 pg/mL) were significantly lower, whereas Klotho was significantly higher (961.0 vs 791 pg/mL) in the treatment vs no treatment group.
Coronary artery calcification developed in a significantly lower proportion of treated patients (55.6% vs 74.3%). The coronary artery calcification score also was significantly lower in the cholecalciferol group (1.16 vs 6.90).
The absence of vitamin D supplementation before and after kidney transplantation significantly increased the odds of persistent hyperparathyroidism by 2.3- and 2.4-fold, respectively, and the odds of coronary artery calcification by 2.1- and 3.5-fold, respectively. Female sex was a significant risk factor for hyperparathyroidism and older age was a significant risk factor for coronary artery calcification.
Other results suggested better graft function over 12 months in the treated group, but more research is warranted.
“Correction of vitamin D deficiency using cholecalciferol within 12 months posttransplant was effective in attenuating persistent hyperparathyroidism, improving FGF23 resistance and high bone turnover status, preserving graft function and preventing coronary calcification,” Dr Shi’s team concluded.
Hu SM, Bai YJ, Li YM, et al. Cholecalciferol supplementation effectively improved tertiary hyperparathyroidism, FGF23 resistance and lowered coronary calcification score: a prospective study. Endocr Connect. Published online July 25, 2022. doi:10.1530/EC-22-0123