There are several sources of vitamin D.
- Plant sources are in the form of vitamin D2. There are few plants that are significant sources of vitamin D.
- Animal sources are in the form of vitamin D3. Some good sources include liver, egg yolk, salmon, sardines, cod, tuna and fish oil. This form is also in our skin and is activated by at least 15 minutes of sunshine each day.
- Another source is foods that are fortified with vitamin D. For example, milk, some brands of butter and cheese, and some breakfast cereal contain added vitamin D.
Once you eat a food containing vitamin D or take a supplement, it goes to the liver and then to the kidneys to be activated. The active form of vitamin D helps keep your bones healthy by balancing calcium and phosphorus. When your kidneys don’t work, vitamin D can’t go through this activation step so you become deficient even if you are taking a supplement or eating foods with vitamin D.
Most kidney patients on dialysis take a prescription form of activated vitamin D to prevent a type of bone disease called renal osteodystrophy. Dietitians routinely monitor and recommend dose adjustments to help manage vitamin D therapy.
The newer research on vitamin D and kidney disease suggests kidney patients, even those on dialysis receiving activated vitamin D, may benefit from supplemental vitamin D3 when blood levels are low. If you have chronic kidney disease in early stages or on dialysis, talk to your doctor about checking your vitamin D level to see if you need a supplement.
