Time out: should vitamin D dosing be based on patient's body mass index (BMI): a prospective controlled study

Abstract

The recommended daily dose of vitamin D is 2000 IU was found to be insufficient in many patients. The objective of the present study is to find whether the daily dose of vitamin D should be based on BMI. Two hundred and thirty patients with an established vitamin D deficiency (serum level of 25 Hydroxy vitamin D3 (25OHD3) of ≤20 ng/ml) and patients with BMI ≥30 kg/m2 were included in the study. Demographic data, comorbidities and BMI were recorded. Pre-treatment and post-treatment serum 25OHD3, calcium, phosphorus and parathyroid hormone (PTH) were tested at 0-, 3- and 6-month periods. Patients were treated with a standard dose of 50 000 IU of vitamin D weekly and 600/1200 mg of calcium a day. Once their level of 25OHD3 reached ≥30 ng/ml, patients were randomised into two groups. Group A received a standard recommended maintenance dose of 2000 IU daily and Group B patients received 125 IU/kg/m2 of vitamin D3. The data were entered in the database and analysed. The mean age of Group A was 50⋅74 ± 7⋅64 years compared to 52⋅32 ± 7⋅21 years in Group B. In both groups, pre-treatment vitamin D level was ≤15 ng/ml and increased to 34⋅6 ± 2⋅6 and 33⋅7 ± 2⋅4 ng/ml at the end of 3 months treatment with a dose 50 000 IU of vitamin D3 and calcium 600/1200 mg once a day for group A and group B, respectively. At 6 months, patients in Group A 25OHD3 level was 22⋅8 ± 3⋅80 and in Group B was 34⋅0 ± 1⋅85 ng/ml (P < 0⋅001). This preliminary study suggests that obese patients need higher dosage of vitamin D than the recommended dose. It is prudent that the dosage should be based on the BMI to maintain normal levels for a healthy musculoskeletal system.

Effect of two vitamin D repletion protocols on 24-h urine calcium in patients with recurrent calcium kidney stones and vitamin D deficiency: a randomized clinical trial

“…This study was a parallel-group randomized controlled clinical trial undertaken in the kidney stone prevention clinic of Shahid Labbafinejad medical center, from April 2018 to May 2020. The patients were recurrent calcium stone formers who had serum 25-hydroxyvitamin D (25(OH)D) level of 10–20 ng/mL, aged 18–70 years, had body mass index (BMI) of less than 30 kg/m 2 [ 12 ], 24-U Ca below 300 mg [ 6 ], normal serum calcium levels who agreed to participate in the study. The recurrent calcium kidney stone was defined as having at least two episodes of radiopaque stones in the past medical history of the patient [ 13 , 14 ].…”

Drug dosing in children with obesity: a narrative updated review

“…The highest percentages of patients with values ≥20 ng/ mL were seen only among the 2000-IU group, implying therefore the superiority in effectiveness of this dose in comparison to the lower ones [43]. No matter what, the question is still open [74].…”

Advances for pediatricians in 2022: allergy, anesthesiology, cardiology, dermatology, endocrinology, gastroenterology, genetics, global health, infectious diseases, metabolism, neonatology, neurology, oncology, pulmonology

“…So far, higher doses are required only for trimethoprim/sulfamethoxazole [44], among antibiotics, midazolam, inhaled corticosteroids. Data on dosing of low molecular weight heparins and vitamin D are unclear [45,46]. So, further investigation on drug dosing are warranted in obese children.…”