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.

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Magnesium (Mg) intake is an important indication of an individual’s Mg status, but no validated food frequency questionnaire (FFQ) to assess intake currently exists. The purpose of this study was to develop and investigate the validity of a semi-quantitative Mg food frequency questionnaire (MgFFQ) against a 14-day food diary to assess average daily Mg intakes. In this cross-sectional study, 135 adults aged 18 to 75 completed the 33-item MgFFQ and a 14-day food diary to assess their Mg intakes. Coefficients of variance, Pearson’s correlation coefficients, and/or Spearman’s rank correlation coefficient tests were used to determine the relationship between the MgFFQ and the average Mg intake from the 14-day food diary among all participants, men, women, age groups, and body mass index (BMI) groups. The correlation between the MgFFQ and the 14-day food diary was significant (p < 0.05) for all participants (r = 0.798), men (r = 0.855), women (r = 0.759), normal weight (r = 0.762), overweight (r = 0.858), and obese (r = 0.675) weight statuses, and in all age groups. The calcium to magnesium intake (Ca:Mg) ratio in all participants was higher than optimal, 3.39 (2.11). Our results suggest that the MgFFQ is a valid method to capture Mg intake over an extended period of time, therefore acting as a valuable tool to quickly determine Mg intake.

Sweetness drives the consumption of added sugars, so understanding how to best measure sweet hedonics is important for developing strategies to lower sugar intake. However, methods to assess hedonic response to sweetness vary, making results across studies difficult to integrate. We compared methods to measure optimal sucrose concentration in 21 healthy adults (1) using paired-comparison preference tracking vs. ratings of liking, (2) with participants in the laboratory vs. at home, and (3) using aqueous solutions vs. vanilla milk. Tests were replicated on separate days to assess test-retest reliability. Test-retest reliability was similar between laboratory and home testing, but tended to be better for vanilla milk and preference tracking. Optimal sucrose concentration was virtually identical between laboratory and home, slightly lower when estimated via preference tracking, and about 50% lower in vanilla milk. However, optimal sucrose concentration correlated strongly between methods, locations, and stimuli. More than 50% of the variability in optimal sucrose concentration could be attributed to consistent differences among individuals, while much less variability was attributable to differences between methods. These results demonstrate convergent validity between methods, support testing at home, and suggest that aqueous solutions can be useful proxies for some commonly consumed beverages for measuring individual differences.

These findings suggest that bone-regulating hormones and nutrients, especially serum PTH, osteocalcin concentrations, and dietary Mg intakes, can help to characterize the MHO phenotype.

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Objectives The ratio of calcium to magnesium (Ca: Mg) intake has gained immense attention in recent years, since a ratio above 2:1 has been associated with increased risk of metabolic, inflammatory and cardiovascular disorders. The objective of this study was to assess Ca: Mg ratios across age groups and to determine the relationship between Ca: Mg ratios and markers of inflammation. Methods Adult men and women, 18 to 60 years of age, completed a demographic form, a magnesium food frequency questionnaire and a calcium food frequency questionnaire. In a subset of individuals, biochemical assays were completed for inflammation markers such as interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), C-reactive protein (CRP) and matrix metallopeptidase 9 (MMP-9). Means, standard deviations, medians and interquartile ranges were calculated, and Pearson's correlations were conducted to determine the relationship between Ca: Mg ratio and markers of inflammation. Results Fifty-six adults were included in this analysis, and were categorized into four age categories: 18 to 29 years, 30 to 39 years, 40 to 49 years and 50 to 59 years. On average, participants were 28.87 ± 10.16 years of age, with a body mass index of 24.54 ± 3.72 kg/m2. Mean magnesium intake, calcium intake and Ca: Mg ratio for each age group were: 249.08 mg, 763.89 mg and 3.37 for the 18–29 years group, 226.59 mg, 730.50 mg and 3.58 for the 30 to 39 years group, 252.63 mg, 731.29 mg and 3.19 for the 40 to 49 years group and 286.03 mg, 595.03 mg and 2.79 mg for the 50 to 59 years group. All study groups had lower magnesium and calcium intakes compared to the Recommended Daily Allowances for these nutrients; however, the Ca: Mg ratio was higher than the optimal ratio of 2:1 in all age groups. In a subset, Ca: Mg ratio was significantly associated with IL-6 (r = 0.626, P = 0.017). Conclusions All age groups had a high Ca: Mg ratio above the optimal 2:1 ratio and in a subset of participants, a higher Ca: Mg ratio was associated with greater inflammation. Interventional studies should target lowering the Ca: Mg ratio in the diet and assess the effect of lowering Ca: Mg ratio on changes in metabolic markers. Funding Sources None.