Background: Vitamin D (Vit D) is a fat-soluble vitamin that supports normal bone development and maintenance by increasing the absorption of calcium, magnesium, and phosphate, which are essential for bone mineralization. Vitamin D is commonly assessed through serum 25-hydroxyvitamin D (25(OH)D) levels, with sufficient levels defined as ≥30 ng/mL, and deficient as < 20 ng/ml. Vitamin D deficiency can lead to rickets in children and osteomalacia or osteoporosis in adults. Despite the successful implementation of vitamin D fortification in foods, deficiency remains common, particularly among individuals with limited sun exposure, poor dietary intake, or disorders that impaired absorption. Recent studies have also shown an association between vitamin D to immune system function, muscle strength, diabetes, and certain cancers. Although vitamin D deficiency is well recognized in the general population, there is limited information on the extent of deficiency in hospitalized patients, particularly in the U.S., highlighting the need for more comprehensive screening and management in vulnerable populations. The purpose of this study is to evaluate the trends of vitamin D, 25 hydroxy levels at Grady Memorial Hospital, a safety-net facility in Atlanta, Georgia that serves a large metropolitan area.
Methods: We performed a cross-sectional observational study of all admitted adult patients (age >18) whose serum vitamin D levels were tested at Grady hospital from January 2013 to October 2024 to determine the prevalence of abnormal (high or low) levels. Slicer Dicer was used to obtain patient data from the EPIC electronic medical record. Serum testing of vitamin D (< 30 ng/ml) indicates deficiency. We followed up with a pilot study to look in greater depth at abnormal samples from 1/1/2024 to 1/17/2024 to examine the proportion that were low and the demographic characteristics of those with deficiencies. Microsoft Excel was used to perform descriptive statistics.
Results: Serum vitamin D, 25 hydroxy levels were ordered 29,037 times between 2013–2024; 23111 samples (79.6%) were labeled abnormal. In the pilot study from 1/1/2024 to 1/17/2024, among 286 patients tested for Vit D, 205 (71.6%) came back “abnormal,” and all tested as deficiently low (< 30 ng/ml). Fifty samples (25%) were ≤7 ng/mL the minimum detected level and another 42 samples (20.5%) were ≤10 ng/ml reflecting severe deficiency. The median age of abnormal Vit D patients was 65 years. 83 of the abnormal low samples (40.5%) were in men and 122 (59%) were in women. 151 patients (73.6%) self-reported Black or African American race while 37 (18%) identified as White or Caucasian. 36 patients (17.5%) of patients had a BMI >30; 52 patients (25.3%) had a normal BMI (between 18.5 and 25); and 10 (4.8%) patients had BMI < 18.5. At the end of the study period, 192 patients (93.6%) were alive and 13 (6.3%) were deceased.
Conclusions: To our knowledge, this is one of the largest data samples of vitamin D testing in admitted patients. Close to three in four samples tested for Vit D level were lower than the minimum cut-off value and close to half the patients had severe deficiency in our pilot study. Though vit D deficiency in hospitalized patients may not reflect vit D deficiency in the general population, the high prevalence of vit D deficiency we observed is alarming. Also, with three in four patients tested for vit D showing deficiency, it is important to investigate the risk factors and specific patient populations that are at risk for developing vit D deficiency and subsequent clinical repercussions.