By: John Wigneswaran MD
Taking a daily multivitamin seems to be a well-established practice for most people. Everyone seems to have a favorite variety, and most Americans feel that this is an important part of a healthy lifestyle. What is usually ignored is that if you are a healthy person and eating a balanced diet, you actually may not need an added multivitamin.

However, for people with kidney disease and even those on dialysis, Multivitamins may be very important for their overall health. In fact, the choices you make in a multivitamin may be even more important because there are certain vitamins and minerals that kidney patients should not take. So what is the right decision?

Among the many reasons why people with kidney disease may become deficient in vitamins and minerals, two major ones are:

  1. Decreased appetite
  2. The body no longer is capable of absorbing and processing every day foods1.

Here are a few kidney nutrition topics that every kidney patient should know:

Malnutrition:

Over the last 20 years many studies have shown that as kidney disease gets worse, kidney patients have a higher risk for malnutrition (sometimes called “protein energy wasting”), which leads to overall lower body vitamin/mineral levels. Dr. Joel Kopple, a past president of the National Kidney Foundation in 2000 and others noted some important facts:

  1. As kidney function became worse and worse, patients take in less protein and calories2, 3,4.
  2. Kidney disease itself worsens the body’s way of handling, absorbing and processing vitamins and minerals.
  3. Vitamin levels change dramatically with some vitamins disappearing from the body quicker, others building up to high levels, and others simply not get ingested to a high amount at all1.
  4. Many of the medications that kidney patients take- and they are on quite a few- may play block the normal absorption of vitamins and minerals from the stomach.

Water-soluble vitamins:

What is a water-soluble vitamin? Its simply those vitamins that dissolve in water- basically your B Vitamins(i.e B complex) and Vitamin C. Why this is very important is that in dialysis patients- patients who need to be connected to a machine to have their blood cleaned every week- water-soluble vitamins get sucked up from the bloodstream as a side effect of the therapy. Another way of thinking about it is that every time a patient gets dialysis, they lose vitamins. Some scientific data pointed out the following facts:

1. If a dialysis patient replaced these “lost” water-soluble vitamins   they tended to live longer5.

2. In patients with kidney disease but not on dialysis yet, studies showed that certain amounts of B vitamins are not only necessary but may be needed in higher

3. B-vitamins can also be low especially when other diseases are present like heart failure (common in kidney patients) 7,8.

4. Lastly, too much of a good thing is just that! For example too much Vitamin C may cause kidney stones and the right amounts should be taken9.

Important Minerals:

What are they? Zinc, copper, and selenium are the important minerals that play a key role in health in patients with kidney disease. Here are some common facts:

  1. Many studies have shown that people with dialysis become quite low in these important minerals.
  2. Zinc, copper and selenium are important parts of our antioxidant enzymes needed for healthy cell function.
  3. Kidney patients tend to start becoming low in these minerals very early – even when they first start to lose kidney function10.
  4. It is important to take a multivitamin that includes the right amounts and types of these minerals if you have kidney disease.

Vitamin D:

Vitamin D is very well known and important vitamin, but it is particularly important in patients who have kidney disease. Here are some important facts about Vitamin D and kidney patients:

  1. Low vitamin D levels are seen in most people with kidney disease, even those on dialysis11,12.
  2. People with even mild kidney disease seem to lose kidney function faster when they had low vitamin D levels13
  3. People with worse kidney disease showed a similar finding (including a higher risk of dying) in people with low vitamin D levels 14.
  4. There seems to be an association between low vitamin D levels and a worse outcome in kidney patients.
  5. Daily doses of 800-1000 IU of Vitamin D have been used in many scientific studies to safely improve Vitamin D levels in people with kidney disease15,16
  6. Patients also need to be careful in taking too much as high Vitamin D doses(1750IU or 2000IU daily) may actually cause more harm than good17.

Guidelines and Reviews:

What do the experts say? Based on the studies we just covered, most experts and national medical groups have issued recommendations that a daily multivitamin in patients with kidney disease is important.

  1. The American Dietetic Association recently advised, “In adults with (kidney disease)… who may be at higher nutritional risk due to poor dietary intake and decreasing (kidney fuction), the (dietitian) should recommend or prescribe a multivitamin preparation”18.
  2. The National Kidney Foundation also took a hard look at multivitamins in kidney disease and agreed that people with kidney disease are more likely to develop deficiencies in many vitamins and minerals as described above19.
  3. Experts agree that Vitamin D levels need to be checked and replaced if low20,21.

People with kidney disease and those on dialysis are at risk for micronutrient deficiencies with potential implications for their health. A well-formulated multivitamin prescribed under the guidance of a nephrologist and dietitian can be an important part of your care. Choosing the right multivitamin that address the unique needs of kidney patients are important. ProRenal is the only multivitamin supported by leading physicians and associations such as the National Kidney Foundation.

References:

  1. Nutritional Management of Renal Disease, Kopple, J (ed) and Massry, S (ed). 2003
  2. Ikizler TA. J Am Soc Nephrol. 1995 Nov;6(5):1386
  3. Kopple JD. Kidney Int. 2000 Apr;57(4):1688
  4. Eustace JA. Kidney Int. 2004 Mar;65(3):1031
  5. Fissell, R. Am J Kidney Dis 2004; 44(2):293.
  6. Kopple, J. Kidney Int. 1981; 19(5):694
  7. Porrini, M. Int J Vitam Nutr Res 1989;69:304
  8. Allard, M. Heart Fail Rev (2006) 11:75
  9. Caring for Australasians with Renal Impairment Clinical Practice Guidelines
  10. Yilmaz, M. Am J Kidney Dis 2006; 47(1):42
  11. LaClair, R Am J Kidney Dis. 2005 Jun;45(6):1026
  12. Saab, G. Nephron Clin Pract 2007;105:c132
  13. de Boer, I. Clin J Am Soc Nephrol 2011 Aug 11 (epub)
  14. Ravani, P. Kidney Int 2009; 75:88
  15. Kooienga, L. Am J Kidney Dis 2009; 53(3):408.
  16. Rucker, D. J Nephrol 2009; 22:75
  17. Michaelsson, K. Am J Clin Nutrition 2010:Aug 18 e-pub
  18. American Dietetic Association Clinical Practice Guideline, Nutrition Recommendations For Chronic Kidney Disease, 2011
  19. Bailey, J. Am J Kidney Dis 2010; 55(6):1146
  20. Kidney Disease Outcomes Quality Initiative – Bone Metabolism, 2004
  21. Kidney Disease Improving Global Outcomes – Mineral and Bone Disorders, 2009