Vitamin D Supplementation in Individuals With a Chronic Spinal Cord Injury

Serum levels of 25(OH)D in nmol/L

Measurements of the forearm (radius), hip (femoral neck) and knee (distal femur and proximal tibia) will be performed using dual-energy X-ray absorptiometry (DXA) scans. T-values will be reported.

Assessed by the Hospital Anxiety and Depression Scale (HADS) questionnaire, using a 4-step scale (1-4) with a total range of 14-56 and higher scores indicating worse outcomes.

Assessed by the Fatigue Severity Scale (FSS) questionnaire, using a 8-step scale (1-7) with total range 9-63 and higher scores indicating worse outcomes.

The occurrence of pain since the last visit is assessed by one question of the SCI Secondary Conditions Scale (Kalpakjian, Scelza et al. 2007), providing a five-step rating (0-4) with a higher score indicating a worse outcome.

The occurrence, kind, location and interference of pain during the last week is assessed using questions of the adapted version of the International SCI Pain Basic Data Set (Widerström-Noga, Biering-Sørensen et al. 2008). The interference of pain is measured on a 11-step scale (0-10), with total range 0-30 and higher scores indicating worse outcomes.

The occurrence, localization and severity of pressure injuries is assessed by the exact questions of the first-wave questionnaire of the Swiss Spinal Cord Injury Cohort Study (SwiSCI) survey (Post, Brinkhof et al. 2011, Brinkhof, Fekete et al. 2016). The severity or grade is assessed using the European and US National Pressure Ulcer Advisory panels' (EPUAP-NPUAP) classification (National Pressure Ulcer Advisory Panel and Alliance. 2014), using a 4 point scale (1-4) and higher grades indicating worse outcomes.

The mean of three measurements of both hands will be measured in kg

The incidence, reason (recreation or daily activity), possible injuries and care needed resulting from each fall since the last visit is assessed by several questions.

Functional independence during daily living will be assessed by the Spinal Cord Independence Measure (SCIM, 3rd version)

Serum levels of calcium (mmol/L) to monitor hypercalcemia

Serum levels of parathyroid hormone (ng/L) will be monitored as it is correlated to vitamin vitamin D status

Serum levels of phosphate (mmol/L) will be monitored as it is correlated to vitamin D status

Serum levels of cystatin C (mg/L) to monitor kidney function

Serum levels of estimated glomerular filtration rate (eGFR) (mL/min) to monitor kidney function

Serum levels of testosterone (ng/dL) will be monitored as it is correlated to vitamin vitamin D status

The occurrence of urinary tract infections since the last visit is assessed by the exact questions of the first-wave questionnaire of the Swiss Spinal Cord Injury Cohort Study (SwiSCI) survey (Post, Brinkhof et al. 2011, Brinkhof, Fekete et al. 2016).

The time spent outdoors (min) with level of exposed skin during the last 7 days, following Hanwell et al (2010).

Six categories ranging from light to very dark skin types based on Fitzpatrick (1975)

Time since SCI (years), neurological level of injury (NLI), and the degree of impairment following the American Spinal Injury Association (ASIA) Impairment Scale (AIS)

Physical activity (hours and number of trainings), medication and nutritional supplements, and illnesses will be assessed by questionnaire. Weight will be measured on a scale.