Vitamins K and D deficiency in severe motor and intellectually disabled patients

We aimed to determine serum 25-hydroxyvitamin D (25(OH)D) and undercarboxylated osteocalcin (ucOC) levels in severe motor and intellectual disabilities (SMID) patients and their association with bone turnover biomarkers.

We assessed vitamin D and K levels as indicators of osteoporosis in institutionalized adults with SMID. From December 2019 to February 2020, 93 institutionalized patients (48 men, 45 women; median age, 49 years) underwent annual routine examinations. Serum ucOC, 25(OH)D, bone-specific alkaline phosphatase (BAP), and tartrate-resistant acid phosphatase A 5b (TRACP-5b) levels as bone formation and resorption markers and calcium and phosphorous levels were measured. Vitamin K deficiency was indirectly assessed based on ucOC levels.

Mean ucOC levels were higher than normal (i.e., vitamin K deficiency). Serum 25(OH)D levels were markedly diminished. Overall, 86% of patients had deficient 25(OH)D levels. These 25(OH)D-deficient patients had higher ucOC levels. Multiple linear regression analysis revealed an inverse correlation between 25(OH)D and ucOC levels. ucOC levels were significantly higher and 25(OH)D levels were significantly lower in tube feeding. TRACP-5b levels were significantly higher in elderly than in young women. BAP and TRACP-5b levels were normal in adults. No relationship existed between vitamin D and antiepileptic drug use.

Vitamin K and D co-deficiency was common in SMID patients. Vitamin K and D deficiencies were worse in tube-fed patients than in oral intake patients. SMID patients should undergo regular monitoring of vitamin D and K levels and supplementation of these vitamins.