What vitamin deficiencies are expected in a patient with longstanding hypertension and chronic kidney disease?

Vitamin Deficiencies Expected in CKD with Hypertension

Patients with chronic kidney disease should be expected to have vitamin D deficiency (universally present), along with deficiencies in water-soluble vitamins including folic acid, vitamin B12, vitamin C, and B-complex vitamins, with the severity and pattern depending on CKD stage and dialysis status.

Vitamin D Deficiency (Universal Finding)

• Vitamin D insufficiency occurs in 80-90% of CKD patients, with levels below 30 ng/mL indicating insufficiency 1
• Vitamin D deficiency is found universally across all CKD stages, including in patients with longstanding hypertension and kidney disease 2
• The deficiency results from reduced sun exposure, limited dietary intake of vitamin D-rich foods, impaired endogenous synthesis in uremic patients, and urinary losses in nephrotic patients 1
• In CKD, 1,25(OH)2D levels correlate directly with 25(OH)D substrate availability, unlike in healthy individuals where this relationship doesn't exist 1

Water-Soluble Vitamin Deficiencies

Folic Acid (Profoundly Deficient)

• Folic acid deficiency is universal and profound across all CKD treatment modalities, including non-dialyzed, hemodialysis, peritoneal dialysis, and transplant patients 3
• Hemodialysis patients lose approximately 0.3 mg of folic acid daily in dialysate, creating ongoing depletion 4
• The typical replacement dose is 1-5 mg daily by mouth to compensate for dialysis losses 4

Vitamin B12 Deficiency

• Vitamin B12 deficiency risk increases with CKD progression, particularly in patients with diabetes and proteinuria 1
• The National Kidney Foundation recommends daily supplementation providing 0.5 mg vitamin B12 for dialysis patients to replace losses 5
• Use methylcobalamin or hydroxocobalamin instead of cyanocobalamin in renal dysfunction, as cyanocobalamin requires renal clearance of cyanide which accumulates in kidney disease 5

Vitamin C Deficiency

• Water-soluble vitamin C is lost during dialysis, with CRRT patients losing approximately 68 mg daily in effluent 6
• The safe upper limit is 100 mg/day for CKD patients to avoid oxalate accumulation, which is particularly dangerous in renal impairment 6
• Malnourished dialysis patients with wounds should be tested for vitamin C deficiency and supplemented with 100 mg/day 6

Other B-Complex Vitamins

• Thiamine, riboflavin, pyridoxine, and pantothenic acid deficiencies occur due to restricted diets, increased losses during dialysis, and inadequate intake 7
• Supplementation with thiamine and other water-soluble vitamins is necessary in peritoneal dialysis and hemodialysis patients to reduce dialysis losses 7
• Vitamin B6 supplementation may be considered to reduce cardiovascular risk in CKD patients 7

Stage-Specific Considerations

Early CKD (Stages 1-3a)

• Vitamin D insufficiency begins early but other vitamin deficiencies may not require intervention if dietary intake is adequate 8, 7
• Monitor for vitamin D levels and supplement when below 30 ng/mL 1

Advanced CKD (Stages 3b-5)

• Supplementation with folate and cobalamin becomes necessary at stage G4 or G5 (uremia) 7
• Niacin at 400-1000 mg daily is required at stage 3b and beyond to lower phosphate levels 7
• Water-soluble vitamin supplementation becomes essential due to increased losses and inadequate intake 9, 7

Dialysis Patients

• Hemodialysis and peritoneal dialysis patients are at highest risk of multiple vitamin deficiencies 3
• Daily vitamin supplementation providing 0.5-5.0 mg folate and 0.5 mg vitamin B12 is recommended to replace dialysis losses 5

Critical Pitfalls to Avoid

• Never start folic acid supplementation without checking B12 levels first, as it may mask hematological deficiency while allowing neurological complications to progress 4
• Avoid routine supplementation of vitamins A and E due to potential toxicity, as vitamin A levels are generally elevated in CKD 8, 9
• Do not exceed 100 mg/day of vitamin C to prevent oxalate accumulation and soft tissue deposition 6
• Avoid cyanocobalamin in favor of methylcobalamin or hydroxocobalamin to prevent cyanide accumulation 5