Context Questions regarding the superiority of free and bioavailable 25-hydroxyvitamin D [25(OH)D] in predicting health outcomes remain unresolved. Objective This study investigates the impact of vitamin D variables—total, bioavailable, or free 25(OH)D—on indices of bone and mineral metabolism, at baseline and in response to 2 vitamin D doses. Design Our objectives are implemented as exploratory analyses on data collected in a 1-year, double-blind, randomized controlled trial completed in July 2014. Setting Participants were recruited from 3 major hospitals in an ambulatory setting. Participants Participants were >65 years of age, overweight, and had a baseline serum 25(OH)D between 10 and 30 ng/mL. A total of 221 participants completed the study. Intervention Subjects were randomized to receive calcium and oral vitamin D3 (600 IU/day or 3750 IU/day) supplementation. Results Participants who received the higher vitamin D dose had levels that were 1.3- to 1.4-fold higher than those taking the lower dose, for all variables (P value < 0.001). Serum values of bioavailable and free 25(OH)D were associated with total 25(OH)D, with r values of 0.942 and 0.943, respectively (P value < 0.001). Parathyroid hormone (PTH) was negatively associated with all vitamin D variables, with correlation coefficients ranging from −0.22 to −0.25, while calcium and bone turnover markers (carboxy-terminal collagen crosslinks and osteocalcin) did not. Only total 25(OH)D had a positive relationship with % change bone mineral density (BMD) at the femoral neck at 12 months, while only free and bioavailable 25(OH) had a positive relationship with % change total body BMD at 12 months. Conclusion Calculated free and bioavailable 25(OH)D do not appear to be superior to total 25(OH)D in predicting indices of bone health in an elderly population.

Emerging evidence has suggested that mushrooms, which are a rich source of the potent antioxidants ergothioneine and glutathione as well as vitamin D, may have neuroprotective properties. This study investigated the association between mushroom consumption and cognitive performance in a nationally representative sample of US older adults. We analyzed data from older adults aged ≥ 60 years from the 2011-2014 National Health and Nutrition Examination Survey. Mushroom intake was measured using up to two 24-hour dietary recalls and was categorized into three groups (lowest, middle, and highest). Cognitive function tests included the Animal Fluency Test (AF); Consortium to Establish a Registry for Alzheimer’s Disease Delayed Recall (CERAD-DR) and Word Learning (CERAD-WL); and Digit Symbol Substitution Test (DSST). Multivariable linear regression models were developed, adjusting for socio-demographics, major lifestyle factors, self-reported chronic diseases, and dietary factors, including the Healthy Eating Index-2015 score and total energy. The study included 2,840 participants. Compared with the lowest category of mushroom intake, participants in the highest category (median intake = 13.4 g /1000 kcal/d) had higher scores for DSST (β = 3.87; 95% confidence interval [CI] 0.30, 7.45; P for trend=0.03) and CERAD-WL (β = 1.05; 95% CI: 0.0003, 2.10; P for trend=0.04). Similar non-significant trends were observed for AF (β = 0.24; 95% CI: −2.26, 2.73; P for trend=0.92) but not for the CERAD-DR. Greater mushroom intake was associated with certain cognitive performance tests, suggesting regular mushroom consumption may reduce the risk of cognitive decline. More research is needed to explore these associations further.

Background Cross-sectional studies suggested that consumption of sulfur amino acids (SAAs) including methionine and cysteine is associated with a higher risk of type 2 diabetes (T2D) in humans and T2D-related biomarkers in animals. But, whether higher long-term SAA intake increases the risk of T2D in humans remains unknown. Objectives We aimed to investigate the association between long-term dietary SAA intake and risk of T2D. Methods We analyzed data collected from two different cohorts of the Framingham Heart Study, a long-term, prospective, and ongoing study. The Offspring cohort (1991–2014) included participants from fifth through ninth exam, and Third-Generation cohort (2002–2011) included participants from first and second exam. After excluding participants with a clinical history of diabetes, missing dietary data or implausible total energy intake, 3,222 participants in the Offspring and 3,205 participants in the Third-Generation cohort were included. Dietary intake was assessed using a validated food frequency questionnaire. The relations between energy-adjusted total SAA (methionine and cysteine) intake or individual SAA intake (in quintiles) and risk of incident T2D were estimated via Cox proportional hazards models after adjusting for dietary and non-dietary risk factors. Associations across the two cohorts were determined by direct combination and meta-analysis. Results During the 23 years follow-up, 472 participants reported a new diagnosis of T2D in the two cohorts. In the meta-analysis, the Hazard Ratios (95% Confidence Interval) of T2D comparing the highest with the lowest intake of total SAAs, methionine, and cysteine were 1.8 (1.3, 2.5), 1.7 (1.2, 2.3), and 1.4 (1.0, 2.1), respectively. The association of SAA intake with T2D was attenuated after adjusting animal protein intake in sensitivity analyses. Conclusions Our findings show that excess intake of SAA is associated with higher risk of T2D. Dietary patterns that are low in SAA diet may help in preventing T2D.

In the Men’s Lifestyle Validation Study (2011-2013), we examined the validity and relative validity of a physical activity questionnaire (PAQ), web-based 24-hour recalls (ACT24) and accelerometers by multiple comparison methods. Over one year, 609 men completed two PAQs, two 7-day accelerometer measures, one doubly labeled water (DLW)-physical activity level (PAL) measure (repeated, n=100), four ACT24s and resting pulse rate. A subset (n=197) completed dual energy X-ray absorptiometry (DXA)(repeated, n=99). The method of triads was used to estimate correlations with true activity using DLW-PAL, accelerometer, and PAQ or ACT24 as alternative comparison measures. Estimated correlations (95% confidence intervals) of the PAQ with true activity were 0.60 (0.52, 0.68) for total activity, 0.69 (0.61, 0.79) for moderate to vigorous physical activity (MVPA), and 0.76 (0.62, 0.93) for vigorous activity. Corresponding correlations for total activity were 0.53 (0.45, 0.63) for the average of four ACT24s and 0.68 (0.61, 0.75) for accelerometer. Total activity and MVPA measured by PAQ, ACT24, and accelerometer were all significantly correlated with body fat and resting pulse rate, which are physiological indicators of physical activity. Using a combination of comparison methods, we found the PAQ and accelerometer to have moderate validity for assessing physical activity, especially MVPA, in epidemiologic studies.