Serum Parathyroid Hormone Responses to Vitamin D Supplementation in Overweight/Obese Adults: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Abstract

Obesity is often associated with vitamin D deficiency and secondary hyperparathyroidism. Vitamin D supplementation typically leads to the reductions in serum parathyroid hormone (PTH) levels, as shown in normal weight individuals. Meanwhile, the dose of vitamin D supplementation for the suppression of PTH may differ in overweight and obese adults. We conducted a systematic review and meta-analysis of randomized controlled trials to determine the dose of vitamin D supplementation required to suppress PTH levels in overweight/obese individuals. We identified 18 studies that examined overweight or obese healthy adults who were supplemented with varying doses of vitamin D3. The primary outcomes examined were changes in PTH and serum 25-hydroxyvitamin D (25OHD) levels from baseline to post-treatment. The results of the meta-analysis showed that there was a significant treatment effect of vitamin D supplementation on PTH, total standardized mean difference (SMD) (random effects) = −0.38 (95% CI = −0.56 to −0.20), t = −4.08, p < 0.001. A significant treatment effect of vitamin D supplementation was also found on 25OHD, total SMD (random effects) = 2.27 (95% CI = 1.48 to 3.06) t = 5.62, p < 0.001. Data from available clinical trials that supplemented adults with D3 ranging from 400 IU to 5714 IU, showed that 1000 IU of vitamin D supplementation best suppressed serum PTH levels, total SMD = −0.58, while vitamin D supplementation with 4000 IU showed the greatest increase in serum 25OH levels. Vitamin D and calcium supplementation of 700 IU and 500 mg, respectively, also showed a significant treatment effect on the suppression of PTH with a total SMD = −5.30 (95% CI = −9.72 to −0.88). In conclusion, the meta analysis of available clinical trials indicates that 1000 IU vitamin D supplementation can suppress serum PTH levels, while 4000 IU of vitamin D was associated with the largest increase in serum 25OHD levels in the overweight and obese population.

The effect of vitamin D supplementation on the glycemic control of pre-diabetic Qatari patients in a randomized control trial

“…When comparing the vitamin D and placebo groups following the intervention period, a decrease was found in PTH in the vitamin D group. This is an expected observation since a reduction of parathyroid hormone has been associated with vitamin D supplementation [35]. Similarly, bilirubin levels were reduced in both groups with more pronounced reduction in the vitamin D group.…”

Low PTH Levels in Adolescents With Anorexia Nervosa

“…The importance of vitamin D and calcium in bone health is well-established and recommendations for the optimal intake of these nutrients is now widely accepted (7). Similar to previous reports in healthy individuals and in certain chronic diseases, the current study found a significant negative association between PTH and 25OHD in correlation analysis (38)(39)(40)(41)(42). The association was noted to be curvilinear with an inflection point at approximately 100 nmol/l of 25OHD visualized in loess curves.…”

Is There Any Threshold for Vitamin D That Elevates Parathyroid Hormone

“…Results from one investigation show that serum 25(OH) D needs to be higher than 31 ng/mL to suppress PTH in normal weight adult populations [55]. Lotito, et al found that, lower doses of vitamin D along with calcium can also significantly suppress PTH in the meta-analysis [56].…”