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The dietary supplement [beta]-hydroxy-[beta]-methylbutyrate (HMB) is claimed to increase strength, lean body mass, and decrease fat mass when used in conjunction with resistance training. Although there is some support for these claims, the evidence is not conclusive, and it is even less so for resistance trained individuals. Therefore, we aimed to further elucidate the effects of HMB supplementation in trained men. A randomized, double-blind, controlled study design was used to investigate the effects of supplementing 22 resistance trained men with 3 g x [d.sup.-1] of HMB or corn starch placebo for 9 weeks with resistance training. The effect of HMB on strength was determined using the 1-repetition maximum (1RM) method for the lower body (leg extension) and upper body (bench press, bicep preacher curl) at baseline and after the supplementation period. Body composition was assessed by skinfolds and bioelectrical impedance analysis (BIA). Overall, 9 weeks' HMB supplementation resulted in a clear-cut, trivial increase in combined averaged strength measures of 1.6% (90% confidence limits: [+ or -] 4.3%). When considered in isolation, however, leg extension 1RM increased by a substantial 9.1% (90% confidence limits: [+ or -] 7.5%), but the effect on upper-body strength was inconclusive (bench press: -1.9 [+ or -] 9.3%; bicep curl: - 1.7 [+ or -] 4.7%). Based on BIA estimates, HMB had a decreasing (although inconclusive) influence on fat mass of -9 [+ or -] 14%, but it had a clear, trivial effect on fat-free mass of 0.2 [+ or -] 2.2%. The magnitude of change in body mass was trivial, but the probability of substantial reductions in skinfold thicknesses ranged from negligible to likely. In previously trained men, supplementation of HMB in conjunction with resistance training provides a substantial benefit to lower-body strength, but it has negligible effects on body composition. KEY WORDS body composition, [beta]-hydroxy-[beta]-methylbutyrate, resistance exercise, 1-repetition maximum, strength

[beta]-Hydroxy-[beta]-Methylbutyrate (HMB)is a popular supplement in the resistance training community, with its use supported by claims of increased strength, muscle growth, and improved recovery; however, research outcomes are variable. Therefore, we meta-analyzed the effectiveness of HMB on strength, body composition, and muscle damage. Nine qualifying studies yielded 14 comparisons subcategorized by training experience (trained, untrained) to provide 12-13 estimates of strength (upper body, lower body, overall average), 13 estimates of fat and fat-free mass, and 7 estimates of the muscle-damage marker creatine kinase. The meta-analysis comprised 394 subjects (age 23 [+ or -] 2 years, mean [+ or -] between-study SD) with 5 [+ or -] 2 weeks' intervention and 5 [+ or -] 6 h x [wk.sup.-1] of training. The estimates were analyzed using a meta-analytic mixed model with study sample size as the weighting factor that included the main-effect covariates to control for between-study differences in HMB dose, intervention duration, training load, and dietary cointervention. To interpret magnitudes, meta-analyzed effects were standardized using the composite baseline between-subject SD and were qualified using modified Cohen effect size thresholds. There were small benefits to lower-body (mean [+ or -] 90% confidence limit: 9.9% [+ or -] 5.9%) and average strength (6.6 [+ or -] 5.7%), but only negligible gains for upper-body strength (2.1 [+ or -] 5.5%) were observed in untrained lifters. In trained lifters, all strength outcomes were trivial. Combined (all studies), the overall average strength increase was trivial (3.7 [+ or -] 2.4%), although uncertainty allows for a small benefit. Effects on fat and fat-free mass were trivial, and results regarding creatine kinase were unclear. Supplementation with HMB during resistance training incurs small but clear overall and leg strength gains in previously untrained men, but effects in trained lifters are trivial. The HMB effect on body composition is inconsequential. An explanation for strength gains in previously untrained lifters requires further research. KEY WORDS covariate, dietary cointervention, mixed model, random effects, standard error

High prevalence of vitamin D deficiency has been reported worldwide. Residents of Taiyuan, China, were predicted to be at high risk of vitamin D deficiency due to its high latitude, heavy air pollution, and cultural sun avoidance. This study investigated the vitamin D status of office workers, and explored the potential determinants of capillary 25-hydroxyvitamin D (25(OH)D) concentration as well as the relationship between 25(OH)D and metabolic syndrome. Two hundred participants, aged 20 to 80 years, were recruited. Capillary dried blood spot (DBS) 25(OH)D was measured; together with anthropometric (height, weight, and waist circumference), biochemical (serum lipid profile and fasting glucose) measures and a lifestyle questionnaire. Thirty-four percent of participants had 25(OH)D concentrations below 30 nmol/L, indicating deficient vitamin D status. Women's 25(OH)D (median; 32.7 nmol/L (upper and lower quartile; 25.8, 43.8)) was significantly lower than men (44.0 nmol/L (32.3, 55.4)) (p < 0.01). Female gender, higher fasting glucose, and increased smoking (p < 0.05) were negatively associated with 25(OH)D concentration. However, there was no association found between metabolic syndrome (MetS) and 25(OH)D concentration and no significant difference in vitamin D status between men or women with MetS compared to healthy individuals. Vitamin D deficiency was common in urban residents of Taiyuan in winter and more so in women than men. [ABSTRACT FROM AUTHOR]

Iodine and selenium are required for thyroid function. This study investigated iodine and selenium intakes in healthy, women aged 50-70 years (n = 97) from three cities in the North Island of New Zealand, after mandatory fortification of bread with iodised salt. Iodine and selenium concentrations were determined in 24-h urine samples; daily intakes were extrapolated from amounts in urine (90% and 55% of daily intake, respectively). Three day diet diaries (3DDD) also estimated selenium and iodine (excluding iodised salt) intake. Median urinary iodine concentration (UIC) was 57 (41, 78) µg/L, indicating mild iodine deficiency. Estimated median iodine intake based on urine was 138 (100,172) µg/day, below Recommended Dietary Intake (RDI) (150 µg/day) with 25% below Estimated Average Requirement (EAR) (100 µg/day). Estimated median selenium intake was 50 (36, 71) µg/day based on urine and 45 (36, 68) µg/day using 3DDD, below RDI (60 µg/day) with 49%-55% below EAR (50 µg/day). Median bread intakes were low at 1.8 (1.1, 2.7) serves/day; 25% consumed ≤1 serve/day. Although population iodine intakes improved following mandatory fortification, some had low intakes. Selenium intakes remain low. Further research should investigate thyroid function of low consumers of iodine fortified bread and/or selenium in New Zealand. [ABSTRACT FROM AUTHOR]

High prevalence of vitamin D deficiency has been reported worldwide. Residents of Taiyuan, China, were predicted to be at high risk of vitamin D deficiency due to its high latitude, heavy air pollution, and cultural sun avoidance. This study investigated the vitamin D status of office workers, and explored the potential determinants of capillary 25-hydroxyvitamin D (25(OH)D) concentration as well as the relationship between 25(OH)D and metabolic syndrome. Two hundred participants, aged 20 to 80 years, were recruited. Capillary dried blood spot (DBS) 25(OH)D was measured; together with anthropometric (height, weight, and waist circumference), biochemical (serum lipid profile and fasting glucose) measures and a lifestyle questionnaire. Thirty-four percent of participants had 25(OH)D concentrations below 30 nmol/L, indicating deficient vitamin D status. Women's 25(OH)D (median; 32.7 nmol/L (upper and lower quartile; 25.8, 43.8)) was significantly lower than men (44.0 nmol/L (32.3, 55.4)) ( p < 0.01). Female gender, higher fasting glucose, and increased smoking ( p < 0.05) were negatively associated with 25(OH)D concentration. However, there was no association found between metabolic syndrome (MetS) and 25(OH)D concentration and no significant difference in vitamin D status between men or women with MetS compared to healthy individuals. Vitamin D deficiency was common in urban residents of Taiyuan in winter and more so in women than men., Competing Interests: The authors declare no conflict of interest. The funding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.