Table 3.
Vitamin K, vitamin D, and bone health in patients with CKD—clinical evidence.
| Reference | Population | Outcome Measure | Main Findings |
|---|---|---|---|
| Vitamin K | |||
| [162] | n = 468, Adult patients with ESRD referred for single kidney transplant | VK, BMD, parameters of mineral metabolism | Poor vitamin K status is highly prevalent among patients with ESRD and associates with inflammation and low aBMD |
| [163] | n = 20, patients with chronic glomerulonephritis | VK, markers of bone metabolism | MK-4 supplementation suppressed bone loss |
| [37] | n = 141, patients with CKD stages 1–4 | PIVKA-II | Subclinical VK deficiency is detectable at just the point in terms of loss of renal function with VC |
| [160] | n = 68, HD patients | VK1, OC, ucOC, iPTH | Suboptimal VK nutriture in HD patients is associated both with increased bone fracture risk and with a high prevalence of hyperparathyroidism |
| Vitamin D | |||
| [164] | n = 104, HD patients | VD, transiliac bone biopsy, ALP, iPTH | PTH serum levels are equally elevated in low and high 25D patients; calcitriol levels are constantly low; 25D deficiency resulted in mineralization and bone formation defect; the optimal level of 25D appears to be in the order of 20 to 40 ng/mL |
| [165] | n = 144, HD patients | VD, iPTH, bone densitometry | Increased bone fragility in HD patients is associated with VD deficiency and relative hypoparathyroidism in addition to reduced BMD at the radius |
| [166] | n = 610, elderly women | VD, BMD | Combined calcium and vitamin D3 supplementation was effective in reducing the rate of BMD loss in women with moderate CKD |
| [167] | n = 120, patients with stages 1–4 CKD | VD, BMD, OC, NTx, FGF-23 | Daily (2000 IU/d) and monthly (40,000 IU/month) VD supplementation for six months in adults with DM and CKD was safe, and it resulted in equivalent adherence and improvements in overall VD status, but only modest changes in markers of bone health |
| [168] | n = 47, CKD patients in stage 3 and 4 | PTH, calcium, creatinine, VD | No statistically significant difference between the two treatments: cholecalciferol (4000 IU/d × 1 month, then 2000 IU/d) to doxercalciferol (1 μg/d) in lowering PTH |
| Vitamin K and Vitamin D | |||
| [3] | n = 172, patients with stage 3 to 5 CKD | VK, VD, ucOC | Proteinuria was associated with both a suboptimal VD status as well as worse peripheral VK status; high serum ucOC levels were positively associated with phosphate and PTH, and inversely with 25D levels |
Abbreviations: ESRD, end-stage renal disease; VK, vitamin K; BMD, bone mineral density; aBMD, areal bone mineral density; MK-4, menaquinone-4; CKD, chronic kidney disease, PIVKA-II, protein induced by VK absence/antagonism II; VC, vascular calcification; HD, hemodialysis; VK1, vitamin K1; OC, osteocalcin; ucOC, uncarboxylated osteocalcin; iPTH, intact parathyroid hormone; ALP, alkaline phosphatase; 25D, 25-hydroxyvitamin D; NTx, N-terminal telopeptide; FGF-23, fibroblast growth factor 23; VD, vitamin D; DM, diabetes mellitus.