Nutritional vitamin D supplements, including cholecalciferol and ergocalciferol, may be inadequate to raise serum total 25-hydroxyvitamin D (25OHD) levels to target range in overweight patients with nondialysis-dependent chronic kidney disease (NDD-CKD), real-world study data suggest.

Extended-release calcifediol may be more effective in this population, according to post hoc analyses of recent trials.

Stephen A. Strugnell, PhD, of OPKO Health, Inc., Miami, Florida, and colleagues analyzed data from 2 real-world studies conducted in Europe and the United States. More than 50% of patients treated with cholecalciferol or ergocalciferol vitamin D supplements failed to achieve serum 25OHD target levels of 30 ng/mL or higher, the investigators reported in the American Journal of Nephrology. In the European study, which included 2459 patients, only 7.3%-7.5% of patients achieved levels of 50 ng/mL or higher. Higher body weight and body mass index (BMI) were associated with lower serum 25OHD levels. According to the investigators, excess weight may impair the ability of vitamin D supplements to raise serum 25OHD.

Continue Reading

In the US study, which included 321 patients, a target serum 25OHD level of 30 ng/mL or higher was achieved by 69.9% of patients treated with extended-release calcifediol, 37% treated with vitamin D supplements, and 6.6% of patients receiving no vitamin D treatments.

The investigators also examined data from 2 randomized controlled trials conducted in the United States. In the first trial of 33 patients, 8 weeks of extended-release calcifediol (60 μg/day) increased serum 25OHD levels to 30 ng/mL or higher and 50 ng/mL or higher in all treated patients, regardless of body weight. Cholecalciferol (300,000 IU/month) increased serum 25OHD to 30 ng/mL or higher in 56% of patients. In the second trial, which included 356 patients, extended-release calcifediol (30 or 60 μg/day) increased mean serum 25OHD levels to at least 50 ng/mL across weight categories, whereas placebo had no effect.

According to Dr Strugnell’s team, nutritional vitamin D supplements are “unreliable” whereas extended-release calcifediol offers “reliable” increase in serum 25OHD to levels in patients with CKD despite overweight.

The studies were not designed to evaluate the effects of body weight and BMI on serum 25OHD, which was a major limitation of this analysis. Other research indicates an increase in certain adverse effects.

Disclosure: This research was supported by Vifor Pharma, Ltd., and the Renal Division of OPKO Health, Inc. Please see the original reference for a full list of disclosures.


Bishop CW, Strugnell SA, Csomor P, Kaiser E, Ashfaq A. Extended-release calcifediol effectively raises serum total 25-hydroxyvitamin D even in overweight nondialysis chronic kidney disease patients with secondary hyperparathyroidism. Am J Nephrol. 2022 May 12;1-9. doi:10.1159/000524289