臨牀透析 Vol.32 No.13(4)

特集名	透析骨症revival―その治療の展開
題名	CKD患者における非活性型ビタミンD製剤の意義
発刊年月	2016年 12月
著者	加藤明彦	浜松医科大学附属病院血液浄化療法部
【要旨】	慢性腎臓病（CKD）患者では早期（ステージG3）からビタミンD欠乏を高率に認め，二次性副甲状腺機能亢進症，腎機能低下の進展，生命予後と関連する．非活性型（天然型/栄養型）ビタミンD製剤は安価で高カルシウム血症のリスクが低く，血清1,25（OH）₂D濃度を上昇させ，血漿副甲状腺ホルモン（PTH）値を下げる．米国では非活性型ビタミンD製剤の処方が急速に増えており，現在では約半数のCKD患者が補充されている．しかし，本邦では血清25（OH）D濃度測定は保険適用されていなかった．また，非活性型ビタミンDも処方薬ではない．今後，非活性型ビタミンD製剤の意義をより明らかにするためには，CKD患者における至適血清25（OH）D濃度やfree/bioactive 25 (OH) D測定の有用性を明らかにするとともに，活性型ビタミンDとの併用療法について検討する必要がある．

Theme	Revival of renal osteodystrophy -- new treatment targeting bone
Title	Role of non-active vitamin D analogues in CKD patients
Author	Akihiko Kato	Blood Purification Unit, Hamamatsu University Hospital
[ Summary ]	In patients with chronic kidney disease (CKD), vitamin D deficiency is highly prevalent as early as at CKD stage G3. This condition is inversely associated with secondary hyperparathyroidism, progression of kidney dysfunction, and increased risk of mortality. Non-active (natural/nutritional) vitamin D is cost-effective with a low risk of hypercalcemia. Supplementation may increase serum levels to 1,25(OH)₂D concentrations and decreases plasma parathyroid hormone (PTH) levels. As a result, the prevalence of nutritional vitamin D supplementation has rapidly increased in the United States, where approximately half of CKD patients are currently being prescribed vitamin D. In Japan, although measurement of serum level of 25(OH)D concentration is recently available, physicians can not prescribe non-active vitamin D as a medical treatment. To clarify the clinical relevance of non-active vitamin D, there is a need to determine optimal concentrations of 25(OH)D and the usefulness of measuring free/bioactive 25(OH)D, as well as testing the effectiveness of combined active and non-active vitamin D agents for CKD patients.