Vitamin D Supplementation in Diabetic Nephropathy
Vitamin D Supplementation in Diabetic Nephropathy
Diabetes is a life-long disease that is getting more common in Canada. One of the most common
 problems in people with kidney disease is diabetes and low bone mineral density (BMD). This
 can lead to a higher chance for broken bones, infection and life-long health problems. The
 most common reason for having low BMD is not getting enough vitamin D (Vit D) in your diet
 and not having enough sunlight. This is very common in Canada (especially in northern
 Alberta) because winter is very long. Most people also don't eat or drink enough foods that
 are high in Vit D (like milk) and so they don't have enough Vit D in their body to make
 healthy bones. This can mean the only way to get enough Vit D in your body for your bones
 when you have kidney disease is to take some extra vitamin D in a pill. Most people are not
 aware that they have poor bone health until they break a bone. Broken bones can really hurt
 and can prevent a person from being able to walk and take care of themselves. Right now, we
 are not sure exactly how much Vit D people with diabetes and kidney disease need to take to
 prevent them from having low BMD or how often they need to take it. Our plan is to study the
 effect of two ways to take Vit D pills (every day or once a month) on overall Vit D status
 and on bone health in adult patients with diabetes and chronic kidney disease and see how
 this influences their quality of life.

 Hypotheses:

 1. Vitamin D supplementation (2,000 IU/day and 40,000 IU/month) for six months will result
 in significantly improved overall vitamin D status and improved markers of bone health
 in adult patients with diabetic nephropathy.

 2. Monthly dosing of vitamin D (40,000 IU/month) over six months will result in improved
 patient adherence and satisfaction with vitamin D supplementation when compared to daily
 dosing of vitamin D (2000 IU/D). This will improve vitamin D status and bone health
 parameters, which will result in an increased quality of life and sense of well-being.
Abstract:

 Vitamin D has a well-established role in bone health and the prevention of fractures which
 are associated with increased morbidity and mortality, and reduced quality of life. However,
 many individuals have sub-optimal vitamin D status (<75nmol/l), and risk increases with
 geographical location, age, ethnicity, inadequate dietary intake and disease. Diabetes and
 kidney disease are two chronic diseases associated with both poor bone health and suboptimal
 vitamin D status. Individuals with diabetes and chronic kidney disease who live in northern
 Alberta are at a particular risk for suboptimal vitamin D status and poor bone health due to
 dietary restrictions on vitamin D rich foods (e.g. milk products that are also high in
 phosphorus and carbohydrates), negligible cutaneous synthesis during the long winter months,
 and reduced renal capacity to synthesize active vitamin D (1,25(OH)2D). In the general
 Canadian population, few are able to meet dietary recommendations for vitamin D intake
 through diet alone and often rely on vitamin D supplements. The need for vitamin D
 supplementation is increased in diabetics with nephropathy, however the optimal dose and
 strategy for vitamin D supplementation is unknown. Like other chronic diseases, adherence to
 therapy is a major issue in this population. With each additional chronic disease an
 individual has, their adherence to therapy and quality of life decreases. Adherence to
 vitamin D therapy is known to be particularly poor. This may be related to the silent nature
 of bone disease, as poor bone health is often not identified until a fracture has occurred.
 Novel strategies to vitamin D supplementation are needed to prevent poor bone health and
 fractures, and the resulting decline in quality of life that ensues. Therefore it is
 important to identify a vitamin D supplementation strategy that increases adherence to
 vitamin D supplementation and improves vitamin D status and bone health in adults with
 diabetes and nephropathy.

 Objectives:

 -  Examine the impact of two approaches to oral high dose vitamin D supplementation (2,000
 IU/day versus 40,000 IU/month for six months) on overall vitamin D status and markers of
 bone turnover in adult patients with diabetic nephropathy.

 -  Examine daily versus monthly vitamin D supplementation strategies in regards to
 adherence, satisfaction and quality of life in adult patients with diabetic nephropathy.

 Hypotheses:

 1. Vitamin D supplementation (2,000 IU/day and 40,000 IU/month) for six months will result
 in significantly improved overall vitamin D status and improved markers of bone health
 in adult patients with diabetic nephropathy.

 2. Monthly dosing of vitamin D (40,000 IU/month) over six months will result in improved
 patient adherence and satisfaction with vitamin D supplementation when compared to daily
 dosing of vitamin D (2000 IU/D). This will improve vitamin D status and bone health
 parameters, which will result in an increased quality of life and sense of well-being.
Inclusion Criteria:

 -  Clinical diagnoses of diabetes (type 1 or 2) and stage 2-4 chronic kidney disease
 (glomerular filtration rate: 15-89 ml/min/1.73m2)

 Exclusion Criteria:

 -  Patients with co-morbid conditions known to affect vitamin D metabolism including
 gastrointestinal, liver, rheumatoid or bone disorders (e.g. hyperthyroidism, untreated
 celiac disease, cancer, Paget's disease, sarcoidosis, malabsorption, etc). Individuals
 with severe, permanent vision impairment will be excluded as this will preclude them
 from reading supplement labels accurately and safely. Pregnant women will be excluded
 as DXA scans are not recommended during pregnancy. Patients weighing >136kg will be
 excluded as the DXA table cannot accommodate this weight.

 -  Patients on drug therapy known to interfere with vitamin D (e.g. oral glucocorticoids,
 cholestyramine, colestipol, mineral oil, Orlistat, digoxin, antacids).

 -  Patients with stage 5 CKD (GFR <15ml/min/1.73m2), receiving dialysis or on kidney
 transplant list.

 -  Patients with pre-existing hypercalcemia (>2.75mmol/l), hyperphosphatemia
 (>2.0mmol/l), severe hyperparathyroidism (PTH >600pg/ml), and serum 25(OH)D
 >200nmol/l.

 -  Patients with serum 25(OH)D <37.5nmol/l at time of study entry/screening to control
 for correction of vitamin D deficiency.