Over the last several years, vitamin D has gained notoriety in mainstream healthcare, but clinicians working in CKD, ESRD, and dialysis have long been aware of this important nutrient.

As CKD progresses, vitamin D levels are compromised due to the kidneys’ declining function and ability to activate vitamin D. This in turn reduces absorption of calcium in the GI tract which leads to increased secretion of parathyroid hormone (PTH). Left untreated, PTH levels will continue to increase and eventually convert to secondary hyperparathyroidism (SHPT).

The consequences of SHPT range from moderate to severe and include abnormal biochemical data, bone disease, vascular calcification, and overall poor health outcomes. To prevent and treat SHPT, clinicians utilize a group of medications to mimic vitamin D and calcium in an effort to optimize PTH levels:

  • Calcitriol = active form of vitamin D3
  • Calcidiol = storage form of vitamin D3
  • Ergocalciferol = vitamin D2
  • Vitamin D Analogs = forms of vitamin D that activate vitamin D receptors to help manage PTH levels and are associated with less hypercalcemia and hyperphosphatemia
    • Examples: doxercalciferol, paricalcitol
  • Calcimimetics = drugs that mimic calcium for calcium sensing receptors to help lower PTH.
    • Examples: Cinacalcet

 

Every time a clinician prescribes one of the above the debate revolves around which delivery is better, IV versus oral delivery. Let’s take a look at the pros and cons of each option:

Compliance

The line of thinking in terms of compliance is that IV = guarantee. Whether it’s vitamin D, medication, or parenteral protein infusion therapy like IDPN, etc. IV administration guarantees the prescribed dose is delivered to the patient as long as they attend dialysis.

When oral administration is used, clinicians must rely on patients to take the recommended prescription unsupervised and do so consistently to see benefit. Adherence to prescriptions is a common challenge observed in the ESRD population which may compromise the effectiveness of oral vitamin D analogs.

Cost

Based on data from the Dialysis Outcomes and Practice Patterns Study (DOPPS), IV delivery of vitamin D analogs has reigned as the most popular choice in part due to Medicare reimbursement guidelines. However, between 2014 and 2017, IV administration declined from 68% to 51% and oral administration saw a concurrent increase. In part, this is due to the fact that oral administration can save as much as $564/person per year.

Mineral and Bone Health Management

Thadani et al reviewed records for 2280 hemodialysis patients and found comparable outcomes in terms of PTH, calcium, and phosphate levels in patients receiving IV vitamin D analogs compared to patients receiving oral calcitriol at 1-year follow-up. They also found hospitalization and survival was comparable.

Infection Risk

Somewhat contradictory to Thadani et al, a study by Tanaka et al looked at 3372 hemodialysis patients and determined those that received IV vitamin D analog administration had significantly reduced incidents of death from infection compared to those receiving oral Vitamin D or no Vitamin D at all. Thus, muddying the waters in terms of health outcomes and Vitamin D delivery.

Overall, research and guidelines agree that some form of vitamin D supplementation is required to maintain better health and control PTH levels in dialysis patients. Due to costs savings, oral delivery will likely grow in popularity, however, many nephrologists may prefer IV delivery for a variety of reasons.

To learn more about CKD mineral and bone disorder management and important micronutrients in ESRD, check out these resources:

  • Clinical Login
    • Access patient handout on phosphate additives, a quick guide to phosphate binders, and more
  • Visit our Library of On-Demand Videos to view our webinar on Micronutrient Concerns for CKD and ESRD

 

References

  • Negrea, L. (2019). Active vitamin D in chronic kidney disease: getting right back where we started from?. Kidney Diseases, 5(2), 59-68.
  • Tanaka, S., Ninomiya, T., Taniguchi, M., Fujisaki, K., Tokumoto, M., Hirakata, H., … & Tsuruya, K. (2016). Comparison of oral versus intravenous vitamin D receptor activator in reducing infection-related mortality in hemodialysis patients: the Q-Cohort Study. Nephrology Dialysis Transplantation, 31(7), 1152-1160.
  • Isakova, T., Nickolas, T. L., Denburg, M., Yarlagadda, S., Weiner, D. E., Gutiérrez, O. M., … & Kramer, H. (2017). KDOQI US commentary on the 2017 KDIGO clinical practice guideline update for the diagnosis, evaluation, prevention, and treatment of chronic kidney disease–mineral and bone disorder (CKD-MBD). American Journal of Kidney Diseases, 70(6), 737-751.