Total joint arthroplasty (TJA) is one of the most common surgical procedures performed in the United States (US), with approximately 2.5 million individuals with total hip arthroplasties (THAs) and 4.7 million individuals with total knee arthroplasties (TKAs) in 2010. Patients who undergo TJA commonly have Vitamin D deficiency, with rates reported to be 24-61% in primary TJA patients. Vitamin D deficiency affects women and minorities at high rates, in addition to non-Hispanic whites. Previous studies demonstrated that Vitamin D deficiency poorly impacts outcomes after various surgical procedures. Specifically in TJA patients, recent studies show a higher rate of Vitamin D deficiency in periprosthetic joint infection (PJI) patients, and a higher rate of postoperative complications and infection in revision TJA patients with low Vitamin D. In a PJI mouse model, Vitamin D-deficient mice were shown to have an increased bacterial burden when compared to Vitamin D-deficient mice that received "rescue" cholecalciferol (Vitamin D3) supplementation. Bacterial burden was similarly decreased between normal mice and the Vitamin D-deficient "rescue" mice receiving supplementation. A single dose of Vitamin D3 supplementation in Vitamin D-deficient mice using the same mouse model reversed the effect of PJI by decreasing bacterial burden and neutrophil infiltration.

The serum concentration of 25-hydroxycholecalciferol or 25-hydroxyvitamin D (25(OH)D) is the most accurate measure of stores of Vitamin D in the body. There are currently different recommendations regarding the optimal serum 25(OH)D level for bone health, the optimal daily intake of Vitamin D, and the treatments for Vitamin D deficiency or insufficiency. These controversial topics do not provide clear clinical guidance on how to optimize Vitamin D levels in surgical patients to reduce complication rates. The US Institute of Medicine (IOM) committee recommended a 25(OH)D level \>20 ng/mL but other organizations recommend ≥30 ng/mL. At present, deficient levels of Vitamin D are generally defined as a 25(OH)D \<20 ng/ml, relative insufficiency as 20 to 29 ng/mL, and sufficient levels as ≥ 30 ng/ml. In 2011, the IOM established Recommended Dietary Allowances (RDAs) for Vitamin D of 600-800 IU/d in order to achieve a 25(OH)D level of 20 ng/ml for 97.5% of the general population. The debate concerns recommendations based upon population science, in contrast to care of an individual patient. Thus, there is continuing debate among several groups that recommend higher Vitamin D3 doses and 25(OH)D levels of ≥30 ng/mL for optimal bone health and in high-risk individuals with osteoporosis. The National Osteoporosis Foundation recommends 800 to 1000 IU Vitamin D3 daily for adults aged 50 years and older, as do the International Osteoporosis Foundation and Endocrine Society. The Endocrine Society recommended even higher doses up to 1500 to 2000 IU/d of Vitamin D3 for older adults. For Vitamin D deficiency, the recommended treatment is 50,000 units of Vitamin D3 weekly for 8 weeks with an assay repeat to determine whether Vitamin D-sufficiency ≥30ng/mL was achieved. The proposed study was designed in light of debated recommendations in the literature and should result in rigorous new information about 25(OH)D levels achieved with different doses of Vitamin D3 supplementation and their impact on post-TJA complications.

There are no current studies in literature examining whether preoperative supplementation and correction of Vitamin D deficiency may reduce complications following TJA. The aim of this randomized controlled trial is to evaluate the ability of different doses (low and high dose) of Vitamin D3 supplementation to affect adverse events and functional outcomes following total joint arthroplasty surgery. To conduct this study, investigators propose randomizing subjects with 25(OH)D levels between 10 and 29 ng/mL to receive different doses of Vitamin D to assess the effects of Vitamin D3 supplementation dosage on postoperative TJA complication rates. Consented patients with serum 25(OH)D levels equal or greater than 30 ng/dL will be included in the control group.