ImPACKD calls for raising awareness about the risks of calcium overuse in CKD patients

New coalition advocates for calcium safety in the CKD community

If you were asked whether calcium is healthy for you, the answer would likely be "yes." But for the 2 million Canadians living with chronic kidney disease (CKD), their answer may be "no."

Most Canadians living with CKD have likely never spoken with their physicians about calcium and the serious health risks associated with its overuse. This is why Improving Patient Advocacy in Chronic Kidney Disease (ImPACKD), a group of CKD patients and caregivers committed to raising awareness about the risks of calcium overuse, is starting the conversation about the importance of knowing the limits and keeping them in check.

"Most CKD patients are unaware that calcium can pose a serious risk to their already delicate health, and I used to be just like them," says Rick Jules, a member of ImPACKD and former councillor for the Tk'emlups Indian Band. "We need information to be able to ask the right questions, be hands-on in our treatment and ensure that we get the best care possible."

Jules, who has CKD and is displaying signs of advanced vascular calcification, underwent quadruple bypass surgery in 2007. "I can attribute a lot of things to the changes in my health but I never thought that a medication that was supposed to help me control the phosphorous levels in my body could lead to a heart problem," states Jules. "If I had understood that taking too much calcium as a phosphate binder could have been bad for me, maybe I would have asked to have my dose scaled back."

Jules' story is not unique. To prevent similar outcomes, international clinical practice guidelines addressing calcium use to treat hyperphosphatemia (too much phosphorous in the blood) have been published by Kidney Disease: Improving Global Outcomes (KDIGO), a not-for-profit organization dedicated to improving patient results. These guidelines suggest that cardiovascular calcification and its progression can be influenced by treatment(1) and recommend that the use of calcium-based phosphate binders be restricted in patients with high blood levels of calcium(2). Furthermore, the guidelines suggest the restriction of calcium based binders in patients with known vascular calcification in patients with CKD, Stage III to V.

Health Canada has established adequate intake limits for calcium supplements, indicating that healthy adult Canadians should ingest 1,000 to 1,200 mg per day, up to a maximum of 1,500 mg(3). However, these limits apply only to healthy Canadians with normal functioning kidneys who are taking calcium to maintain good health. These people are able to eliminate excess minerals in their urine, something CKD patients cannot do. As calcium accumulates, CKD patients are thought to be put at risk of organ and tissue calcification, vascular calcification and cardiovascular events. A Canada-wide study of dialysis patients suggests that the daily calcium intake from phosphate binders may be double or triple the maximum limit established by Health Canada(4). Furthermore, CKD patients are taking this level of calcium consistently over an extended period of time.

"Calcium overuse among CKD patients is a problem that has a solution, whether it is a change in medication or a reduction in dietary calcium intake," says Dr. David Mendelssohn, chief and physician director of the Department of Nephrology, Humber River Regional Hospital in Toronto, and a Medical Advisor for ImPACKD.

Recent Canadian research supports KDIGO guidelines, suggesting that calcium-based phosphate binders used by CKD patients may be placing them at risk of cardiovascular disease and death. A systematic review of calcium usage among CKD patients published in Nephrology Dialysis Transplantation (NDT) found a strong trend suggesting an increased risk of death among patients taking calcium-based phosphate binders(5), signalling a potential safety issue related to the use of calcium-based phosphate binders.

"Although calcium-based phosphate binders are an effective compound in the treatment of CKD, they need to be prescribed in moderation so we can maintain an optimal mineral balance for patients rather than removing one mineral and loading them up with another," adds Dr. Mendelssohn. "As nephrologists, we need to consider guidelines and understand the ramifications of what we are prescribing to our patients."

"Bringing this issue to the attention of guideline decision-makers, through patients and physicians reporting all adverse side effects of calcium, will help to bridge the gap between the perceived benefits of calcium and the reality of its affect on those with CKD," says Dr. Sophie Jamal, director of the multidisciplinary osteoporosis program at Woman's College Hospital in Toronto and medical advisor to ImPACKD.

Education and empowerment are driving ImPACKD's efforts, emphasizing that patients should demand access to treatment alternatives and full information regarding risks and benefits of treatments from all health care professionals. "This vital information is necessary so people can make informed choices, but this is not the case with calcium overuse as it pertains to CKD," says Hugh O'Reilly, a Toronto lawyer with a special interest in patient advocacy. "Health Canada needs to provide guidance to the CKD community on its established calcium intake limit and clarify this as it relates to CKD patients. Lastly, safety issues need to be considered nation-wide by the provinces in order to provide access to the required treatment options for Canadians."