Dairy calcium intake, serum vitamin D, and successful weight loss

Associations between vitamin D, immunoglobulin E concentrations, and obesity

The prevalence of allergies and obesity has been increased in parallel. Low vitamin D [25(OH)D] levels have been linked to both higher body mass index (BMI) and allergies. Since the activation of the 25(OH)D receptor inhibits IgE production and 25(OH)D influences the IgE response specifically, we tested the hypothesis that circulating 25(OH)D concentrations are negatively related to circulating allergen-specific IgE concentrations distinctly in a large adult population-based study cohort. Moreover, we studied VDR gene expression in paired biopsies of abdominal subcutaneous (SAT) and visceral adipose tissue (VAT). We investigated whether magnetic resonance imaging-estimated visceral (VFM) and subcutaneous fat mass (SFM) are related to 25(OH)D levels. We found gender differences in circulating 25(OH)D and IgE concentrations. Participants with obesity showed lower 25(OH)D concentrations and higher IgE concentrations were detected in women only. Interestingly, participants with high levels of 25(OH)D are leaner and have improved glucose metabolism. In women, 25(OH)D correlate significant with VFM and SFM. VDR expression is significantly higher expressed in VAT and is positive associated with circulating 25(OH)D concentration. There was no association between serum IgE and 25(OH)D in the entire cohort. Based on these data, we could confirm that low levels of 25(OH)D are linked to higher BMI but could not prove our hypothesis because there is no relationship between 25(OH)D and IgE in adults. Women with higher BMI tend to have higher IgE levels what may have clinical relevance. The association between obesity and circulating 25(OH)D/IgE is not straightforward, and further knowledge is needed.

Correlation between 25-hydroxy vitamin D levels in women and in vitro fertilization outcomes: A cross-sectional study

Background

Vitamin D has recently raised a great deal of controversy, not because of its traditional role of absorbing calcium and maintaining bone health, but because of its unconventional role as an endocrine factor and the extent of its impact when linked to its specific receptors (VDR) found in different tissues. Research has raced trying to find its different roles in those tissues and its association with different clinical or medical conditions, and among these cases, its role in reproductive functions and fertility in women, these studies conflicted between supporting and denying the role of vitamin D in reproductive function and rejecting this hypothesis according to the results of their study.

Materials and methods

The in vitro fertilization process allowed us to study the possible hypotheses, as this technique provides an opportunity to study the relationship between vitamin D levels with the in vitro fertilization outcomes, thus providing us with an idea of the relationship of vitamin D with fertility in women. In order to study this relationship, we designed our research as a cross-sectional study to confirm or deny this claim. Vitamin D was measured in the blood and in the follicular fluid for all cases using the electrochemiluminescence immunoassay (ECLIA) for the assay of total vitamin D, then IVF outcomes were compared with the levels of vitamin D in the blood.

Results

the levels of vitamin D are not related to the criteria of eggs such as the number of eggs and the maturity rate (MR) of eggs, but they are correlated in a statistically significant manner with the fertility rate (FR), and at the same time the levels of vitamin D in the blood were completely independent of the clinical pregnancy rate (CPR).

Conclusion

blood vitamin D levels will affect the FR when its levels in the blood drop below a specified value, vitamin D did not correlate with the CPR. In the long run, there is scope for more research projects on vitamin D. Future research could include case-control studies of patients on vitamin D supplementation, and the study of its correlation with IVF outcomes.

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Vitamin D deficiency affects various body functions including reproductive system in females.

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Appropriate levels of blood 25-hydroxy vitamin D affect the egg fertility rate, while it does not affect the maturity rate.

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Adequate levels of 25-hydroxy vitamin D are not associated with clinical pregnancy rates during in vitro fertilization.

Daily intake of yogurt drink fortified either with vitamin D alone or in combination with added calcium causes a thyroid-independent increase of resting metabolic rate in adults with type 2 diabetes: a randomized double blind clinical trial

We investigated the effect of daily intake of yogurt drink fortified with either vitamin D alone or with added calcium on resting metabolic rate (RMR), thyroid hormones and homeostatic model assessment for insulin resistance (HOMA-IR) in subjects with type 2 diabetes (T2D). A total of 75 adult subjects with T2D were randomly assigned to one of the three groups to receive either D-fortified yogurt drink (DY; 1000 IU vitamin D/d), Ca-D-fortified yogurt drink (CDY; 1000 IU vitamin D plus 500 mg calcium), or plain yogurt drink (PY) for 12 weeks. All assessments were done at the baseline and after the intervention. The concentrations of anti-thyroid peroxidase antibody (anti-TPO-Ab), intact parathyroid hormone (iPTH) and thyroid stimulating hormone (TSH) had significant decline compared with baseline values only in CDY group. The mean RMR increased in both DY and CDY groups (p<0.001 for both). Also, changes of serum concentrations of 25(OH)D (B= 2.96, 95%CI= 1.3- 4.6, p=0.001) and iPTH (B= -2.41, 95%CI= -4.5- -0.31, p=0.025) remained significant predictors of RMR changes even after adjustment for changes of serum concentrations of TSH (B= -18.2, 95%CI= -61.7- 25.2, p=0.406). Daily intake of vitamin D together with calcium at physiological doses has attenuating effect on anti-TPO-Ab and TSH. Also, vitamin D with or without added calcium causes a significant thyroid-independent increase in RMR in euthyroid subjects with T2D. Registered at clinicaltrials.gov as NCT01229891. Novelty: Daily intake of vitamin D with calcium at physiological doses has attenuating effect on anti-TPO-Ab and TSH. Vitamin D with or without added calcium causes a thyroid-independent increase in RMR in euthyroid subjects with T2D.

Calcium Intake Is Inversely Related to Risk of Obesity among American Young Adults over a 30-Year Follow-Up

BACKGROUND

Calcium (Ca) is an essential nutrient that may play an important role in weight maintenance through its involvement in energy or lipid metabolism. However, little is known about the long-term associations of Ca intake with obesity risk.

OBJECTIVES

We aimed to prospectively examine the association between cumulative Ca intake and the incidence of obesity among American young adults over 30 y of follow-up.

METHODS

Participants were from the CARDIA (Coronary Artery Risk Development in Young Adults) study. A total of 4097 of 5115 black and white individuals aged 18-30 y at baseline in 1985-1986 were included in the current analysis. Dietary and supplemental Ca intake was assessed by the validated interview-based CARDIA diet history at baseline and exam years 7 and 20. Incident cases of obesity were identified when BMI was ≥30 kg/m2 for the first time since baseline. A survival analysis was performed using Cox proportional hazards regression models to estimate the HRs and corresponding 95% CIs for obesity incidence during follow-up.

RESULTS

During a 30-y follow-up (mean ± SD: 20 ± 10 y), 1675 participants developed obesity. Cumulative total Ca intake (dietary plus supplemental Ca) was inversely associated with incidence of obesity in multivariable-adjusted analysis [quintile (Q)5 (highest intake) compared with Q1 (lowest intake): HR: 0.68; 95% CI: 0.56, 0.82; P-trend < 0.01]. This inverse association persisted among Ca supplement users (Q5 compared with Q1: HR: 0.53; 95% CI: 0.40, 0.70; P-trend < 0.01), but was not seen among nonusers.

CONCLUSIONS

Following a cohort of Americans from young adulthood to midlife, an inverse association between calcium intake and obesity incidence was observed. Further studies are needed to confirm our findings.

Parathyroid Hormone and 25-Hydroxyvitamin D Do Not Mediate the Association between Dietary Calcium, Protein and Vitamin D Intake and Adiposity and Lipid Profile in Patients with Type 2 Diabetes: a Structural Equation Modeling Approach

This study aimed to utilize structural equation modeling (SEM) techniques to determine the effects of dietary calcium, protein and vitamin D on adiposity and lipidemia and to assess mediatory effects of parathyroid hormone (PTH) and 25-hydroxyvitamin D (25(OH)D) in patients with type 2 diabetes. In this cross-sectional study, a total of 150 diabetic patients (93 females and 57 males) were randomly selected. Anthropometric measures, biochemical analyses, and fat mass percent were recorded. Nutritional data were collected. SEM was performed. Based on the primary hypothesis, adiposity and lipidemia were fitted in a model. The direct effects of dietary calcium (λ = -0.165, p value = 0.002) and PTH (λ = -0.143, p value = 0.011) were significantly associated with lipidemia. There were no significant effects for dietary protein on PTH (λ = -0.270, p value = 0.057), 25(OH)D (λ = -0.071, p value = 0.613), lipidemia (λ = -0.044; p value = 0.638) or adiposity (λ = -0.009, p value = 0.949) as well as for dietary vitamin D on PTH (λ = -0.119, p value = 0.194), 25(OH)D (λ = 0.023, p value = 0.806), lipidemia (λ = 0.034, p value = 0.587) or adiposity (λ = -0.221, p value = 0.118). The correlation between calcium intake and lipidemia, and adiposity are not mediated by 25(OH)D and PTH. There were the direct effects of dietary calcium on adiposity in patients with type 2 diabetes. The model can be tested in future longitudinal and intervention studies to identify the predictors of obesity.

Differential Impact of Calcium and Vitamin D on Body Composition Changes in Post-Menopausal Women Following a Restricted Energy Diet and Exercise Program

Vitamin D and calcium supplementation have been posited to improve body composition and different formulations of calcium may impact bioavailability. However, data are lacking regarding the combinatorial effects of exercise, diet, and calcium and/or vitamin D supplementation on body composition changes in post-menopausal women. Herein, 128 post-menopausal women (51.3 ± 4.5 years, 36.4 ± 5.7 kg/m², 46.2 ± 4.5% fat) were assigned to diet and supplement groups while participating in a supervised circuit-style resistance-training program (3 d/week) over a 14-week period. Diet groups included: (1) normal diet (CTL), (2) a low-calorie, higher protein diet (LCHP; 1600 kcal/day, 15% carbohydrates, 55% protein, 30% fat), and (3) a low-calorie, higher carbohydrate diet (LCHC; 1600 kcal/day, 55% carbohydrates, 15% protein, 30% fat). Supplement groups consisted of: (1) maltodextrin (PLA), (2) 800 mg/day of calcium carbonate (Ca), and (3) 800 mg/day of calcium citrate and malate and 400 IU/day of vitamin D (Ca+D). Fasting blood samples, body composition, resting energy expenditure, aerobic capacity, muscular strength and endurance measures were assessed. Data were analyzed by mixed factorial ANOVA with repeated measures and presented as mean change from baseline [95% CI]. Exercise training promoted significant improvements in strength, peak aerobic capacity, and blood lipids. Dieting resulted in greater losses of body mass (CTL -0.4 ± 2.4; LCHC -5.1 ± 4.2; LCHP -3.8 ± 4.2 kg) and fat mass (CTL -1.4 ± 1.8; LCHC -3.7 ± 3.7; LCHP -3.4 ± 3.4 kg). When compared to LCHC-PLA, the LCHC + Ca combination led to greater losses in body mass (PLA -4.1 [-6.1, -2.1], Ca -6.4 [-8.1, -4.7], Ca+D -4.4 [-6.4, -2.5] kg). In comparison to LCHC-Ca, the LCHC-Ca+D led to an improved maintenance of fat-free mass (PLA -0.3 [-1.4, 0.7], Ca -1.4 [-2.3, -0.5], Ca+D 0.4 [-0.6, 1.5] kg) and a greater loss of body fat (PLA -2.3 [-3.4, -1.1], Ca -1.3 [-2.3, -0.3], Ca+D -3.6 [-4.8, -2.5]%). Alternatively, no significant differences in weight loss or body composition resulted when adding Ca or Ca+D to the LCHP regimen in comparison to when PLA was added to the LCHP diet. When combined with an energy-restricted, higher carbohydrate diet, adding 800 mg of Ca carbonate stimulated greater body mass loss compared to when a PLA was added. Alternatively, adding Ca+D to the LCHC diet promoted greater% fat changes and attenuation of fat-free mass loss. Our results expand upon current literature regarding the impact of calcium supplementation with dieting and regular exercise. This data highlights that different forms of calcium in combination with an energy restricted, higher carbohydrate diet may trigger changes in body mass or body composition while no impact of calcium supplementation was observed when participants followed an energy restricted, higher protein diet.

Effects of Vitamin D Status and Supplements on Anthropometric and Biochemical Indices in a Clinical Setting: A Retrospective Study

CONTEXT

Obesity and low vitamin D status are linked. It is not clear that weight loss through lifestyle intervention is influenced by vitamin D status.

OBJECTIVE

The aim of this study was to investigate the effect of baseline vitamin D status and vitamin D supplementation on weight loss and associated parameters for participants on a weight loss program in a primary care setting.

DESIGN

A retrospective analysis of clinical records of patients who underwent an individually tailored weight loss program at a single dietetic clinic in Sydney, Australia.

SETTING

Primary care centers.

PATIENTS

205 overweight and obese men and women aged from 18 to 50 years.

INTERVENTIONS

Patients were referred to a dietetic clinic for a weight loss program. Patients with low serum 25-hydroxyvitamin D (25(OH)D) concentrations at baseline were advised to increase sun exposure and take multivitamins supplemented with 2000 IU or 4000 IU per day of vitamin D3, according to the preference of their primary care physician.

MAIN OUTCOME MEASURES

Clinical parameters of weight, height, waist circumference, and serum 25(OH)D, as well as blood pressure and fasting lipid profile were collected from both baseline and three-month follow-up consultations.

RESULTS

Subjects with sufficient baseline 25(OH)D levels (≥50 nmol/L) experienced significantly greater weight loss (-7.7 ± 5.9 kg vs. -4.2 ± 3.3 kg) and reductions in BMI (-2.6 ± 1.8 kg/m² vs. -1.5 ± 1.1 kg/m²) and waist circumference (-5.2 ± 3.5 cm vs. -3.1 ± 3.1 cm) as compared with those who were vitamin D insufficient at baseline (p < 0.001 for all). Vitamin D insufficient patients who were supplemented with daily 2000 IU or 4000 IU vitamin D experienced significantly greater decreases in weight (-5.3 ± 3.6 kg vs. -2.3 ± 1.6 kg), BMI (-1.9 ± 1.2 kg/m² vs. -0.8 ± 0.6 kg/m²) and waist circumference (-4.2 ± 3.4 cm vs. -1.2 ± 1.3 cm) as compared with those not supplemented (p < 0.001 for all). We also observed a greater decrease in low-density lipoprotein (LDL) cholesterol (-0.4 ± 0.5 mmol/L vs. -0.2 ± 0.5 mmol/L) in subjects insufficient at baseline and supplemented as compared with those insufficient at baseline and not supplemented (p < 0.01).

CONCLUSION

In a weight loss setting in a dietetic clinic, adequate vitamin D status at baseline, or achieved at three months through supplementation, was associated with significantly greater improvement of anthropometric measures. The study has implications for the management of vitamin D status in obese or overweight patients undergoing weight loss programs.

Vitamin D and Cardio-Metabolic Risk Factors in Overweight Adults: An Overview of the Evidence

BACKGROUND

Several studies have suggested a potential association between low vitamin D serum levels and several pathological conditions apart from the well-known bone disorders. Thus, vitamin D insufficiency has been linked to cardiometabolic risk factors including obesity, insulin resistance, hypertension, dyslipidemia, as well as type 2 diabetes and cardiovascular disease.

OBJECTIVE

This review intends to provide an overview of recent evidence from clinical studies on vitamin D [25- hydroxyvitamin D (25(OH)D)] and cardiometabolic risk factors in overweight adults. Furthermore, we also discussed potential mechanisms and limits of the retrieved results.

METHODS

The search process was based on the selection of publications (RCT) listed in PubMed and Cochrane Library databases.

RESULTS

Vitamin D status evidenced an inversely strong association with subcutaneous adipose tissue and visceral adiposity, but not significantly related to other bodyweight measures (i.e., body mass index). Studies have shown a potential inverse association of hypovitaminosis D with insulin resistance and cardiovascular risk factors.

CONCLUSION

The mechanisms by which vitamin D deficiency enhances adiposity, as well as putative association with metabolic syndrome features, remain still unclear. Further investigation would be required to conclude whether vitamin D has an independent role in preventing cardiometabolic disorders.

'The hunger trap hypothesis': New horizons in understanding the control of food intake

The global obesity epidemic continues to present significant challenges to individuals and healthcare providers. Public health initiatives to tackle the rise in overweight and obesity in developed and developing nations have largely failed to tackle the problem and research into the underlying causes is of increasing importance. Central to understanding overconsumption of calories is an appreciation of the mechanisms of hunger and satiety. Research to date has revealed considerable detail regarding meal size, macronutrient composition of the diet and control of energy balance via adipose store derived signalling. It is clear however that such control mechanisms are overwhelmed in a significant proportion of the population. We hypothesize the hitherto under-researched possibility that micronutrient status may have an important role in energy balance. Poor vitamin and mineral profiles in the diets of the obese may potentiate overconsumption of calories due to an insufficiency of micronutrient intake relative to macronutrient consumption, a situation aggravated by increased requirements in the obese state. Amongst the multiplicity of metabolic and biochemical processes dependent upon micronutrients and which are impacted by their relative insufficiency, there may be triggers for increased food consumption in an attempt to bridge the gap between high energy consumption and low co-factor availability. This 'hunger trap' will continue as long as low nutrient density foods represent the mainstay of the diet. The accepted paradigm of variety seeking leading to vitamin and mineral adequacy of diets may not apply in the context of highly processed foods which use technological means to mimic organoleptic properties of nutrient density without delivering the same at the level of metabolism.

Role of Calcium and Low-Fat Dairy Foods in Weight-Loss Outcomes Revisited: Results from the Randomized Trial of Effects on Bone and Body Composition in Overweight/Obese Postmenopausal Women

Several studies have investigated the possibility of dairy foods and calcium (Ca) mediating weight and body composition, but a consensus has not been reached. We aimed to investigate weight-loss-related outcomes during intervention with low-fat dairy foods or Ca + vitamin D supplements, both as complements to hypocaloric diets. Overweight/obese Caucasian, early-postmenopausal women (n = 135) were recruited for a 6 month energy-restricted weight loss study complemented with either low-fat dairy foods (D; 4–5 servings/day), or Ca + vitamin D supplements (S); both to amount a total of ~1500 mg/day and 600 IU/day of Ca and vitamin D, respectively, or placebo pills (C). Bone mineral density (BMD) and lean and fat tissue were measured by Lunar iDXA. Serum and urinary markers of bone turnover were analyzed. Diet and physical activity were assessed with 3-day records. Participants on average lost ~4%, ~3%, and ~2% of body weight, fat, and lean tissue, respectively. The significantly better outcomes were noticed in participants in the D group regarding body composition (fat loss/lean tissue preservation) and in participants in the S group regarding the BMD outcomes, compared to those in the C group. Therefore, increasing low-fat dairy foods to 4–5 servings/day and/or increasing Ca & vitamin D intake by supplements (in those who are at the borderline dietary intake) may be beneficial for weight loss/maintenance and may lead to more favorable bone and body composition outcomes in postmenopausal women during moderate weight loss.

Vitamin D supplementation and muscle strength in pre-sarcopenic elderly Lebanese people: a randomized controlled trial

Previous studies have shown that improving vitamin D status among the elderly may lead to an improvement in muscle mass and muscle strength. In our study, vitamin D supplementation showed significant improvements in vitamin D concentrations as well as appendicular muscle mass in pre-sarcopenic older Lebanese people. However, we found no significant effect on muscle strength.

INTRODUCTION

Improving vitamin D status might improve muscle function and muscle mass that lead to sarcopenia in older subjects. The aim of this randomized, controlled, double-blind study was to examine the effect of vitamin D supplementation on handgrip strength and appendicular skeletal muscle mass in pre-sarcopenic older Lebanese subjects. We also examined whether this effect differs in normal vs. obese subjects.

METHODS

Participants (n = 128; 62 men and 66 women) deficient in vitamin D (25(OH)D = 12.92 ± 4.3 ng/ml) were recruited from Saint Charles Hospital, Beirut, Lebanon. The participants were given a supplement of 10,000 IU of cholecalciferol (vitamin D group; n = 64) to be taken three times a week or a placebo tablet (placebo group; n = 64) for 6 months. One hundred fifteen subjects completed the study: 59 had normal weight, while 56 were obese. Strength and functional assessment and biochemical analysis were performed at the start and after 6 months.

RESULTS

Compared to placebo, the vitamin D supplemented group showed significant improvements in appendicular skeletal muscle mass (ASMM) (P < 0.001) but not in handgrip strength (P = 0.2901). ANCOVA for ASMM adjusting for obesity and including the interaction between obesity and vitamin D showed a significant interaction. The increase in ASMM with vitamin D in normal-weight subjects was higher than that of obese subjects (B = 35.09 vs. B = 2.19).

CONCLUSION

Treatment with vitamin D showed beneficial effects on appendicular muscle mass in pre-sarcopenic older Lebanese men and women. However, it had no effect on muscle strength relative to placebo. This trial was registered at isrctn.org as ISRCTN16665940.

Vitamin D supplementation and body fat mass: a systematic review and meta-analysis

Studies have indicated that 25-hydroxyvitamin D (25(OH)D) level in obese is lower than normal weight subjects; however, results of studies that investigated relationship between 25(OH)D and fat mass are inconsistent. In addition, several randomized clinical trials (RCTs) have studied the influence of cholecalciferol supplement on percentage fat mass (PFM) but their results are conflicting. The objectives were to investigate the association between vitamin D3 and PFM pooling together observational studies and RCTs. PubMed/MEDLINE, Cochrane, and Scopus were comprehensively searched from inception to September 2016. The Fisher's Z (SE) of correlation coefficient and mean (SD) of changes in PFM from baseline were used to perform meta-analysis in observational studies and RCTs, respectively. To determine potential source of heterogeneity, subgroup and meta-regression analyses were conducted. Pooling correlation coefficients showed an inverse association between PFM (Fisher's Z: - 0.24, 95% CI: - 0.30 to -0 .18) and FM (Fisher's Z: - 0.32, 95% CI: - 0.43 to - 0.22) and 25(OH)D. Subgroup analysis revealed continent but not gender influence on the effect size. Meta-regression analysis indicated that age, latitude, and longitude are not sources of heterogeneity. Combining trials showed vitamin D3 supplementation had a mild but insignificant effect on PFM (- 0.31%, 95% CI: - 1.07 to 0.44). Subgroup analyses indicated that type of cholecalciferol and treatment regimens explain source of heterogeneity. Age, baseline body mass index, dose of cholecalciferol, length of study, female (%), and baseline 25(OH)D are not source of heterogeneity. In conclusion, our results state that 25(OH)D level is inversely correlated with PFM but cholecalciferol supplementation had no effect on PFM.

Effect of Multi-Ingredient Supplement Containing Satiereal, Naringin, and Vitamin D on Body Composition, Mood, and Satiety in Overweight Adults

The purpose of this investigation was to examine the effects of 28 days of a dietary supplement on body composition, mood, and satiety in overweight adults. Twenty healthy adults (25.5 ± 3.8 years; 87.3 ± 20.7 kg; 169.9 ± 10.6 cm; 29.9 ± 5.1 body mass index) participated in this randomized, double-blind, placebo-controlled investigation. Ten participants were provided with a dietary supplement containing 178 mg satiereal, 100 mg naringin, and 2,000 IU vitamin D3 daily (SUPP), and ten participants were provided a placebo (PL) for 28 days. Baseline (PRE) and post (POST) assessments included body mass, BMI, and waist circumference measures. In addition, participants provided self-reported food records and completed study questionnaires twice weekly. Questionnaires consisted of profile of mood states, visual analog scales, modified trait food-cravings questionnaire, and a modified state food-cravings questionnaire. No significant differences were noted between groups for total calorie or macronutrient intake (p = 0.65-0.92), body mass (p = 0.34), BMI (p = 0.24), or waist circumference measures (p = 0.56-0.94). In addition, no significant differences between groups were observed for mood states, subjective measures of food cravings, or feelings of anxiety, fullness, bloating, hunger, craving, and stress (p >.05). In conclusion, 28 days of a dietary supplement containing satiereal, naringin, and vitamin D3 did not have any detectable beneficial effects on body-weight management.

Significance of long chain polyunsaturated fatty acids in human health

In the last decades, the development of new technologies applied to lipidomics has revitalized the analysis of lipid profile alterations and the understanding of the underlying molecular mechanisms of lipid metabolism, together with their involvement in the occurrence of human disease. Of particular interest is the study of omega-3 and omega-6 long chain polyunsaturated fatty acids (LC-PUFAs), notably EPA (eicosapentaenoic acid, 20:5n-3), DHA (docosahexaenoic acid, 22:6n-3), and ARA (arachidonic acid, 20:4n-6), and their transformation into bioactive lipid mediators. In this sense, new families of PUFA-derived lipid mediators, including resolvins derived from EPA and DHA, and protectins and maresins derived from DHA, are being increasingly investigated because of their active role in the "return to homeostasis" process and resolution of inflammation. Recent findings reviewed in the present study highlight that the omega-6 fatty acid ARA appears increased, and omega-3 EPA and DHA decreased in most cancer tissues compared to normal ones, and that increments in omega-3 LC-PUFAs consumption and an omega-6/omega-3 ratio of 2-4:1, are associated with a reduced risk of breast, prostate, colon and renal cancers. Along with their lipid-lowering properties, omega-3 LC-PUFAs also exert cardioprotective functions, such as reducing platelet aggregation and inflammation, and controlling the presence of DHA in our body, especially in our liver and brain, which is crucial for optimal brain functionality. Considering that DHA is the principal omega-3 FA in cortical gray matter, the importance of DHA intake and its derived lipid mediators have been recently reported in patients with major depressive and bipolar disorders, Alzheimer disease, Parkinson's disease, and amyotrophic lateral sclerosis. The present study reviews the relationships between major diseases occurring today in the Western world and LC-PUFAs. More specifically this review focuses on the dietary omega-3 LC-PUFAs and the omega-6/omega-3 balance, in a wide range of inflammation disorders, including autoimmune diseases. This review suggests that the current recommendations of consumption and/or supplementation of omega-3 FAs are specific to particular groups of age and physiological status, and still need more fine tuning for overall human health and well being.

Dietary fat composition, total body fat and regional body fat distribution in two Caucasian populations of middle-aged and older adult women

OBJECTIVE

We aimed to study whether dietary fat composition (n-3 and n-6 polyunsaturated fatty acids ratio (PUFAs) and PUFAs and saturated fatty acids (SFAs) ratio) is associated with total body fat (TF) and body fat distribution and whether this association was modified by the presence of chronic disease in middle-aged and elderly women in two population-based cohorts in the Netherlands and Australia.

METHODS

The study was performed in the Rotterdam Study (RS), a prospective cohort study among subjects aged 55 years and older (N = 1182 women) and the Calcium Intake Fracture Outcome Study (CAIFOS), a 5-year randomized controlled trial among women age 70+ (N = 891). At baseline, diet (i.e. PUFAs and SFAs) was measured by validated food frequency questionnaires. TF was assessed using Dual-energy X-ray absorptiometry in both studies and android abdominal fat (AF), gynoid fat (GF) and the android/gynoid ratio (A/G ratio) in the RS but not the CAIFOS. Chronic disease was defined as the presence of cardiovascular disease, diabetes mellitus and cancer.

RESULTS

No association was found between dietary n-3/n-6 PUFAs ratio or SFA/PUFAs ratio with TF in both cohorts. In the RS, a high n-3/n-6 PUFAs ratio was associated with a higher AF (3rd vs. 2nd tertile (reference): β: 0.15; 95% CI: 0.05, 0.24) but not with the A/G ratio. A low SFA/PUFA ratio was associated with a lower AF (1st vs. 2nd tertile (reference): β: -0.12; 95% CI: -0.22, -0.06) but not with the A/G ratio. Presence of chronic disease was found to be a significant effect modifier in both cohorts with regard to n-3/n-6 PUFAs and TF (P < 0.05). In participants without chronic disease, a higher n-3/n-6 PUFAs ratio was associated with a higher TF in the RS cohort (3rd vs. 2nd tertile (reference): β: 0.94; 95% CI: 0.12, 1.76), but this was not replicated in CAIFOS.

CONCLUSION

These findings do not support the hypothesis that dietary fat composition is consistently associated with TF and body fat distribution in women. Future studies should clarify to what extent these findings may be influenced by the presence of chronic disease.

Calcium intake: good for the bones but bad for the heart? An analysis of clinical studies

The proper dietary calcium intake and calcium supplementation, when indicated, are important factors in the acquisition of peak bone mass during youth and in the prevention of fractures in old age. In addition to its deposition in bone, calcium confers an increase in its resistance and exhibits important activities in different enzymatic pathways in the body (e.g., neural, hormonal, muscle-related and blood clotting pathways). Thus, calcium supplementation can directly or indirectly affect important functions in the body, such as the control of blood pressure, plasma glucose, body weight, lipid profile and endothelial function. Since one publication reported increased cardiovascular risk due to calcium supplementation, many researchers have studied whether this risk actually exists; the results are conflicting, and the involved mechanisms are uncertain. However, studies that have evaluated the influence of the consumption of foods rich in calcium have reported no increase in the cardiovascular risk, which suggests that nutritional intake should be prioritized as a method for supplementation and that the use of calcium supplements should be reserved for patients who truly need supplementation and are unable to achieve the recommended daily nutritional intake of calcium.

A randomized trial of high-dairy-protein, variable-carbohydrate diets and exercise on body composition in adults with obesity

OBJECTIVE

This study determined the effects of 16-week high-dairy-protein, variable-carbohydrate (CHO) diets and exercise training (EXT) on body composition in men and women with overweight/obesity.

METHODS

One hundred and eleven participants (age 47 ± 6 years, body mass 90.9 ± 11.7 kg, BMI 33 ± 4 kg/m(2) , values mean ± SD) were randomly stratified to diets with either: high dairy protein, moderate CHO (40% CHO: 30% protein: 30% fat; ∼4 dairy servings); high dairy protein, high CHO (55%: 30%: 15%; ∼4 dairy servings); or control (55%: 15%: 30%; ∼1 dairy serving). Energy restriction (500 kcal/day) was achieved through diet (∼250 kcal/day) and EXT (∼250 kcal/day). Body composition was measured using dual-energy X-ray absorptiometry before, midway, and upon completion of the intervention.

RESULTS

Eighty-nine (25 M/64 F) of 115 participants completed the 16-week intervention, losing 7.7 ± 3.2 kg fat mass (P < 0.001) and gaining 0.50 ± 1.75 kg lean mass (P < 0.01). There was no difference in the changes in body composition (fat mass or lean mass) between groups.

CONCLUSIONS

Compared to a healthy control diet, energy-restricted high-protein diets containing different proportions of fat and CHO confer no advantage to weight loss or change in body composition in the presence of an appropriate exercise stimulus.

Dairy consumption in association with weight change and risk of becoming overweight or obese in middle-aged and older women: a prospective cohort study

BACKGROUND

Studies have reported inconsistent findings on the association between dairy product intake and weight change and obesity. Only a few prospective studies have investigated the role of dairy consumption in both weight change and risk of becoming overweight or obese and whether these associations depend on the initial body weight.

OBJECTIVE

We prospectively investigated how dairy product intake was associated with weight change and risk of becoming overweight or obese in initially normal-weight women.

DESIGN

We studied 18,438 women aged ≥45 y from the Women's Health Study who were free of cardiovascular disease, cancer, and diabetes and had initial body mass index (BMI; in kg/m(2)) from 18.5 to <25 at baseline. Dairy intake was assessed with the use of a 131-item food-frequency questionnaire. Women self-reported body weight along with obesity-related risk factors on baseline and annual follow-up questionnaires. At each follow-up time, women were categorized as normal weight (BMI: 18.5 to <25), overweight (BMI: 25 to <30), or obese (BMI ≥30).

RESULTS

During a mean follow-up of 11.2 y, 8238 women became overweight or obese. Multivariable-adjusted mean ± SD changes in body weight during the follow-up (18 y) were 1.90 ± 0.09, 1.88 ± 0.08, 1.86 ± 0.09, 1.82 ± 0.09, and 1.65 ± 0.09 kg in quintiles 1-5 of total dairy intake, respectively (P-trend = 0.003). Greater intake of high-fat dairy products, but not intake of low-fat dairy products, was associated with less weight gain (P-trend = 0.004). In multivariable-adjusted analyses, lower risk of becoming overweight or obese was observed in the highest quintile of high-fat dairy product intake (HR: 0.92, 95% CI: 0.86, 0.99). Dietary or supplemental calcium or vitamin D was not associated with risk of becoming overweight or obese.

CONCLUSION

Greater consumption of total dairy products may be of importance in the prevention of weight gain in middle-aged and elderly women who are initially normal weight.

Dietary Influence on Calcitropic Hormones and Adiposity in Caucasian and African American Postmenopausal Women Assessed by Structural Equation Modeling (SEM)

OBJECTIVES

To examine differences in hydroxycholecalciferol (25(OH)D) and parathyroid hormone (PTH) concentrations between Caucasian and African American (AA) postmenopausal women, as well as the effects of dietary calcium, protein and vitamin D intakes on 25(OH)D, PTH, and body adiposity using structural equation modeling (SEM).

DESIGN

Population-based prospective cohort study.

SETTING

Academic research using the baseline data from two longitudinal studies. Participants Included n=113 Caucasian and n=40 African American, postmenopausal women who completed the baseline data collection and met inclusion criteria (dietary calcium intake <900 mg/day and being generally healthy) between 2006 and 2010.

MAIN OUTCOME

Dietary intake of calcium and vitamin D, assessed by dietary records, were examined in relation to calcitropic hormones concentrations and adiposity markers. Independent t-tests, confirmatory factor analysis, SEM and multi-group analyses were conducted to examine the aforementioned relationships as well as group differences among hormones, dietary intake, anthropometrics, age and other factors.

RESULTS

Dietary calcium and protein intakes were significantly lower in AA women. Years since menopause were significantly higher in AA compared to Caucasian women. PTH and 25(OH)D levels were significantly lower in AA compared to Caucasian women. Dietary calcium and protein intakes did not influence body adiposity in either group of women. Dietary vitamin D had minimal indirect (via 25(OH)D levels) influence on adiposity.

CONCLUSION

The study confirmed the positive relationship of 25(OH)D with adiposity markers and both AA and Caucasian women. The study provides a unique example of the use of SEM in nutrition research within a clinical context. This model should be further tested in other populations.

Cardiorespiratory fitness in older adult women: relationships with serum 25-hydroxyvitamin D

Previous studies suggest that circulating 25(OH)D may favorably influence cardiorespiratory fitness and fat oxidation. However, these relationships have not been examined in older adult women of different ethnic groups. The objectives of this study were to determine whether serum 25(OH)D is related to cardiovascular fitness (VO2max) in sedentary women ages ≥60 years and to determine whether these associations differ between African Americans (AA) and European Americans (EA). A secondary aim was to determine whether serum 25(OH)D is correlated with respiratory quotient (RQ) during submaximal exercise. This cross-sectional analysis included 67 AA and EA women ages 60-74 years. VO2max was measured by a modified Bruce graded treadmill protocol, and measurements were adjusted for percent fat and lean body mass assessed by air displacement plethysmography. Indirect calorimetry was used to measure RQ at rest and during four submaximal exercise tests. Fasting blood samples were obtained to quantify serum 25(OH)D. Serum 25(OH)D was associated with VO2max (ml/kg LBM/min) independent of percent body fat (r = 0.316, p = 0.010). However, subgroup analysis revealed that this relationship was specific to AA (r = 0.727, p = 0.005 for AA; r = 0.064, p = 0.643 for EA). In all subjects combined, 25(OH)D was inversely correlated (p < 0.01) with all measures of submaximal RQ. Higher serum 25(OH)D was associated with greater cardiorespiratory fitness in older adult AA women. Among both AA and EA, inverse associations between serum 25(OH)D and RQ suggest that women with higher levels of circulating vitamin D also demonstrated greater fat oxidation during submaximal exercise.

Milk, dairy products, and their functional effects in humans: a narrative review of recent evidence

Milk is a widely consumed beverage that is essential to the diet of several millions of people worldwide because it provides important macro- and micronutrients. Milk is recognized as being useful during childhood and adolescence because of its composition; however, its relatively high saturated fat proportion raises issues of potential detrimental effects, namely on the cardiovascular system. This review evaluates the most recent literature on dairy and human health, framed within epidemiologic, experimental, and biochemical evidence. As an example, the effects of milk (notably skimmed milk) on body weight appear to be well documented, and the conclusions of the vast majority of published studies indicate that dairy consumption does not increase cardiovascular risk or the incidence of some cancers. Even though the available evidence is not conclusive, some studies suggest that milk and its derivatives might actually be beneficial to some population segments. Although future studies will help elucidate the role of milk and dairy products in human health, their use within a balanced diet should be considered in the absence of clear contraindications.

New reference values for calcium

The nutrition societies of Germany, Austria and Switzerland are the joint editors of the 'reference values for nutrient intake'. They have revised the reference values for the intake of calcium and published them in June 2013. The reference values for the calcium intake for infants are derived from the calcium content of breast milk. For infants from 4 to <12 months of age, the calcium intake from solid foods is included in addition to the calcium intake from breast milk. Thus, the reference values for infants are estimated values; they are 220 mg/day for infants to <4 months and 330 mg/day for infants from 4 to <12 months of age. As a parameter for determining the calcium requirement in children and adolescents, calcium retention is taken into account. The average requirement is calculated by the factorial method. A balanced calcium metabolism is calculated based upon calcium balance studies and used as a parameter for the determination of the calcium requirement in adults. On the basis of the average requirement, recommended calcium intake levels for children, adolescents and adults are derived. Depending on age, the recommended calcium intake ranges between 600 mg/day for children aged 1 to <4 years and 1,200 mg/day for adolescents aged 13 to <19 years; for adults, it is 1,000 mg/day.

Hypovitaminosis D and incidence of obesity: a prospective study

The aim of this study was to assess the relationship between obesity and vitamin D status cross-sectionally, the relationship between obesity and the incidence of hypovitaminosis D prospectively and inversely the relationship between vitamin D status and incidence of obesity in a population-based cohort study in Spain. At baseline (1996-1998), 1226 subjects were evaluated and follow-up assessments were performed in 2002-2004 and 2005-2007, participants undergoing an interview and clinical examination with an oral glucose tolerance test. At the second visit, 25-hydroxyvitamin D and intact parathyroid hormone concentrations were also measured. Prevalence of obesity at the three visits was 28.1, 36.2 and 39.5%, respectively. The prevalence of vitamin D deficiency (25-hydroxyvitamin D ≤ 20 ng/ml (≤ 50 nmol/l)) was 34.7%. Neither obesity at baseline (OR=0.98, 95% CI: 0.69-1.40, P=0.93) nor the development of obesity between baseline and the second evaluation (OR=0.80, 95% CI: 0.48-1.33, P=0.39) were significantly associated with vitamin D status. In subjects who were non-obese (BMI <30 kg/m²) at the second evaluation, 25-hydroxyvitamin D values ≤ 17 ng/ml (≤ 42.5 nmol/l) were significantly associated with an increased risk of developing obesity in the next 4 years (OR=2.35, 95% CI: 1.03-5.4, P=0.040 after diverse adjustments). We conclude that vitamin D deficiency is associated with an increased risk of developing obesity.

Dietary calcium intake is associated with adiposity, metabolic profile, inflammatory state and blood pressure, but not with erythrocyte intracellular calcium and endothelial function in healthy pre-menopausal women

Recent studies have suggested that dietary Ca may have beneficial effects on adiposity, insulin resistance, dyslipidaemia and blood pressure (BP). One potential mechanism underlying these benefits involves modifications in intracellular Ca concentration ([Ca2+]i). The present study aimed to evaluate the associations of dietary Ca with adiposity, erythrocyte [Ca2+]i, metabolic profile, BP, inflammatory state and endothelial function in healthy pre-menopausal women. In the present cross-sectional study, seventy-six women aged 18–50 years were submitted to the evaluation of dietary intake, anthropometric parameters, body composition, erythrocyte [Ca2+]i, biochemical variables, endothelial function and BP. A FFQ was used to assess usual dietary intake. Endothelial function was evaluated by serum concentrations of adhesion molecules and by the peripheral arterial tonometry (PAT) method, using Endo-PAT 2000®. Participants were allocated into two groups according to Ca intake: low-Ca group (LCG; n 32; < 600 mg/d) and high-Ca group (HCG; n 44; ≥ 600 mg/d). Women in the LCG compared with those in the HCG exhibited, after adjustments for potential confounders, higher values of BMI, waist circumference, waist:height ratio, percentage of body fat, insulin, homeostasis model assessment of insulin resistance, leptin, diastolic and mean BP; and lower levels of HDL-cholesterol, adiponectin and vascular cell adhesion molecule 1. Endothelial function assessed by PAT and [Ca2+]i was similar in both groups. Subjects in the HCG had lower OR for prevalent overweight, obesity, abdominal obesity, insulin resistance, HDL-cholesterol < 600 mg/l and systolic BP >120 mmHg. The findings of the present study suggest that high Ca intake is inversely associated with some cardiovascular risk factors.

Possible role of hyperinsulinemia and insulin resistance in lower vitamin D levels in overweight and obese patients

A cohort of 66 healthy overweight and obese patients, 53 women and 13 men were examined. Waist circumference and fasting 25(OH)D, insulin, glucose, lipid (cholesterol, HDL cholesterol, and triglyceride), C-reactive protein (CRP), and complement 3 (C₃), and 4 (C₄) serum concentrations were measured. Insulin resistance was assessed by the homeostasis model assessment (HOMA_IR). Results. 25(OH)D levels showed a significant negative correlation with BMI (P < 0.01), waist circumference (P < 0.05), fasting insulin (P < 0.01), HOMA_IR (P < 0.01), triglycerides (P < 0.01), CRP (P < 0.01), C₃ (P < 0.05), and C₄ (P < 0.05). Multiple regression analyses were performed with 25(OH)D as the dependent variable and BMI (or waist circumferences), fasting insulin (or HOMA_IR), triglycerides, and CRP (or C₃ or C₄) as independent variables. Only insulin or HOMA_IR maintained a significant independent association with 25(OH)D levels, whereas vitamin D did not maintain a significant independent association with CRP or C₃ or C₄ concentrations. Conclusions. The present study, performed in overweight and obese subjects, shows that 25(OH)D levels are negatively associated with inflammatory parameters such as CRP and C₃ and C₄ levels, but not independently of BMI, body fat distribution, insulin levels, or insulin resistance. Our results suggest that hyperinsulinemia and/or insulin resistance are directly responsible for decrease of 25(OH)D levels in obesity.

25-Hydroxyvitamin D Supplementation and BMI Change: A Meta-Analysis of Randomized Controlled Trials

The impact of 25-hydroxyvitamin D (25[OH]D) supplementation on weight change remains controversial. The objective of this study was to summarize the effects of 25[OH]D supplementation (cholecalciferol or ergocalciferol) on BMI change through a meta-analysis of published clinical trials. We completed a systematic review of English articles, using MEDLINE (Ovid, Pubmed) from January 1, 1998 through January 1, 2013. The articles selected focused on 25[OH]D supplementation and body mass index (BMI) in randomized controlled trials (RCT’s). The association between 25[OH]D and mean BMI change was estimated utilizing a random effects model. A total of 30 studies were reviewed and 9 were included in the meta-analysis. Total participants included 1651 adults (82.6% women and mean age 47.9 years) and mean follow-up ranged between 6 to 196 weeks and mean daily 25[OH]D dose ranged from 200 IU to 1,110 IU. Five of the 9 studies included calcium supplementation in both groups. Average baseline BMI was 30.7 and 30.4 kg/m² in the intervention and control groups, respectively. Five studies suggested a beneficial effect for 25[OH]D supplementation for BMI change whereas 3 studies showed no effect of 25[OH]D supplementation on BMI change, and one showed a non-perceptible change. Meta-analysis of BMI values at end of trial showed no statistically significant difference in BMI change by use of 25[OH]D supplementation. Based on existing published trials, oral 25[OH]D supplementation does not significantly impact BMI change.

Associations between 25-hydroxyvitamin D and weight gain in elderly women

BACKGROUND

25-Hydroxyvitamin D [25(OH)D] levels are lower in obese individuals. Determining whether low vitamin D status can predispose weight gain requires a longitudinal study.

METHODS

From a community-based multicenter U.S. prospective cohort of 9704 (Study of Osteoporotic Fractures [SOF]), 4659 women aged ≥65 with baseline 25(OH)D measurement were followed for 4.5 years. They were weighed at baseline and follow-up visits, and a subset (n=1054) had 25(OH)D levels remeasured at follow-up.

RESULTS

Women with 25(OH)D levels ≥30 ng/mL had lower baseline weight (141.6 pounds) compared to women with 25(OH)D levels <30 ng/mL (148.6 pounds) (p<0.001). Overall, 25(OH)D status was not associated with weight change over 4.5 years, although there was a significant interaction between 25(OH)D status and weight change category (loss, gain, stable) (p<0.0001). In women who gained ≥5% weight, those with baseline 25(OH)D levels ≥30 ng/mL gained 16.4 pounds (12.2% of baseline weight) over 4.5 years compared to 18.5 pounds (13.9% of baseline weight) in women with levels <30 ng/mL (p=0.04). In women who lost ≥5% weight or remained stable (<5% weight change), there was no association between 25(OH)D status at baseline and weight change. Among women who gained weight and had 25(OH)D measured at both visits, having sustained or developing 25(OH)D levels ≥30 ng/mL was associated with less weight gain between visits (14.81 vs. 16.34 pounds, p=0.04).

CONCLUSIONS

Higher 25(OH)D levels are associated with lower weight gains, suggesting low vitamin D status may predispose to fat accumulation.

Does calcium intake affect cardiovascular risk factors and/or events?

Dietary intervention is an important approach in the prevention of cardiovascular disease. Over the last decade, some studies have suggested that a calcium-rich diet could help to control body weight, with anti-obesity effects. The potential mechanism underlying the impact of calcium on body fat has been investigated, but it is not fully understood. Recent evidence has also suggested that a calcium-rich diet could have beneficial effects on other cardiovascular risk factors, such as insulin resistance, dyslipidemia, hypertension and inflammatory states. In a series of studies, it was observed that a high intake of milk and/or dairy products (the main sources of dietary calcium) is associated with a reduction in the relative risk of cardiovascular disease. However, a few studies suggest that supplemental calcium (mainly calcium carbonate or citrate) may be associated with an increased risk of cardiovascular events. This review will discuss the available evidence regarding the relationship between calcium intake (dietary and supplemental) and different cardiovascular risk factors and/or events.

Calcium and vitamin D supplementation is associated with decreased abdominal visceral adipose tissue in overweight and obese adults

BACKGROUND

Several studies suggest that calcium and vitamin D (CaD) may play a role in the regulation of abdominal fat mass.

OBJECTIVE

This study investigated the effect of CaD-supplemented orange juice (OJ) on weight loss and reduction of visceral adipose tissue (VAT) in overweight and obese adults (mean ± SD age: 40.0 ± 12.9 y).

DESIGN

Two parallel, double-blind, placebo-controlled trials were conducted with either regular or reduced-energy (lite) orange juice. For each 16-wk trial, 171 participants were randomly assigned to 1 of 2 groups. The treatment groups consumed three 240-mL glasses of OJ (regular or lite) fortified with 350 mg Ca and 100 IU vitamin D per serving, and the control groups consumed either unfortified regular or lite OJ. Computed tomography scans of VAT and subcutaneous adipose tissue were performed by imaging a single cut at the lumbar 4 level.

RESULTS

After 16 wk, the average weight loss (∼2.45 kg) did not differ significantly between groups. In the regular OJ trial, the reduction of VAT was significantly greater (P = 0.024) in the CaD group (-12.7 ± 25.0 cm(2)) than in the control group (-1.3 ± 13.6 cm(2)). In the lite OJ trial, the reduction of VAT was significantly greater (P = 0.039) in the CaD group (-13.1 ± 18.4 cm(2)) than in the control group (-6.4 ± 17.5 cm(2)) after control for baseline VAT. The effect of calcium and vitamin D on VAT remained highly significant when the results of the 2 trials were combined (P = 0.007).

CONCLUSIONS

The findings suggest that calcium and/or vitamin D supplementation contributes to a beneficial reduction of VAT. This trial is registered at clinicaltrial.gov as NCT00386672, NCT01363115.

Dietary fat and not calcium supplementation or dairy product consumption is associated with changes in anthropometrics during a randomized, placebo-controlled energy-restriction trial

Insufficient calcium intake has been proposed to cause unbalanced energy partitioning leading to obesity. However, weight loss interventions including dietary calcium or dairy product consumption have not reported changes in lipid metabolism measured by the plasma lipidome.

Increased consumption of dairy foods and protein during diet- and exercise-induced weight loss promotes fat mass loss and lean mass gain in overweight and obese premenopausal women

Weight loss can have substantial health benefits for overweight or obese persons; however, the ratio of fat:lean tissue loss may be more important. We aimed to determine how daily exercise (resistance and/or aerobic) and a hypoenergetic diet varying in protein and calcium content from dairy foods would affect the composition of weight lost in otherwise healthy, premenopausal, overweight, and obese women. Ninety participants were randomized to 3 groups (n = 30/group): high protein, high dairy (HPHD), adequate protein, medium dairy (APMD), and adequate protein, low dairy (APLD) differing in the quantity of total dietary protein and dairy food-source protein consumed: 30 and 15%, 15 and 7.5%, or 15 and <2% of energy, respectively. Body composition was measured by DXA at 0, 8, and 16 wk and MRI (n = 39) to assess visceral adipose tissue (VAT) volume at 0 and 16 wk. All groups lost body weight (P < 0.05) and fat (P < 0.01); however, fat loss during wk 8-16 was greater in the HPHD group than in the APMD and APLD groups (P < 0.05). The HPHD group gained lean tissue with a greater increase during 8-16 wk than the APMD group, which maintained lean mass and the APLD group, which lost lean mass (P < 0.05). The HPHD group also lost more VAT as assessed by MRI (P < 0.05) and trunk fat as assessed by DXA (P < 0.005) than the APLD group. The reduction in VAT in all groups was correlated with intakes of calcium (r = 0.40; P < 0.05) and protein (r = 0.32; P < 0.05). Therefore, diet- and exercise-induced weight loss with higher protein and increased dairy product intakes promotes more favorable body composition changes in women characterized by greater total and visceral fat loss and lean mass gain.

Food composition of the diet in relation to changes in waist circumference adjusted for body mass index

Background

Dietary factors such as low energy density and low glycemic index were associated with a lower gain in abdominal adiposity. A better understanding of which food groups/items contribute to these associations is necessary.

Objective

To ascertain the association of food groups/items consumption on prospective annual changes in “waist circumference for a given BMI” (WC_BMI), a proxy for abdominal adiposity.

Design

We analyzed data from 48,631 men and women from 5 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Anthropometric measurements were obtained at baseline and after a median follow-up time of 5.5 years. WC_BMI was defined as the residuals of waist circumference regressed on BMI, and annual change in WC_BMI (ΔWC_BMI, cm/y) was defined as the difference between residuals at follow-up and baseline, divided by follow-up time. The association between food groups/items and ΔWC_BMI was modelled using centre-specific adjusted linear regression, and random-effects meta-analyses to obtain pooled estimates.

Results

Higher fruit and dairy products consumption was associated with a lower gain in WC_BMI whereas the consumption of white bread, processed meat, margarine, and soft drinks was positively associated with ΔWC_BMI. When these six food groups/items were analyzed in combination using a summary score, those in the highest quartile of the score – indicating a more favourable dietary pattern –showed a ΔWC_BMI of −0.11 (95% CI −0.09 to −0.14) cm/y compared to those in the lowest quartile.

Conclusion

A dietary pattern high in fruit and dairy and low in white bread, processed meat, margarine, and soft drinks may help to prevent abdominal fat accumulation.

Dairy consumption and overweight and obesity: a systematic review of prospective cohort studies

A comprehensive literature search was undertaken to examine the relationship between dairy consumption and overweight/obesity in prospective cohort studies. A literature search from 1980 through to April 2010 was conducted. Nineteen cohort studies met all the inclusion criteria and were included in the systematic review. Of the 19 cohort studies, 10 were among children and adolescents (aged 2 to 14 years, n = 53 to 12,829, follow-up 8 months to 10 years) and nine among adults (aged 18 to 75 years, n = 248 to 42,696, follow-up 2 years to 12 years). A range of dairy food exposure measures were used. Eight studies (three out of 10 studies involving children and five out of nine studies involving adults) showed a protective association against increasing weight gain (measured in various ways); one reported a significant protective association only among men who were initially overweight; seven reported no effect; one reported an increased risk (among children), and two reported both a decreased and increased risk, depending on the dairy food type. The evidence from prospective cohort studies for a protective effect of dairy consumption on risk of overweight and obesity is suggestive but not consistent, making firm conclusions difficult.

The link between obesity and low circulating 25-hydroxyvitamin D concentrations: considerations and implications

Obesity and vitamin D deficiency have both been recognized as major public health issues worldwide, and there is growing evidence that they are related, although the cause-effect relationship remains unclear. Could obesity be contributing to low circulating 25-hydroxyvitamin D concentrations? Alternatively, could low vitamin D status predispose to obesity? In this review, the relationship between low circulating 25-hydroxyvitamin D and obesity, and possible underlying reasons from both perspectives, is presented. One potential mechanism by which obesity could contribute to low serum 25-hydroxyvitamin D is adipose sequestration of vitamin D. On the other hand, adipose tissue has both the vitamin D receptor and the ability to synthesize 1,25-dihydroxyvitamin D, and there is evidence that vitamin D may regulate adipose tissue mass, differentiation and metabolism in ways that might contribute to obesity. Of particular interest, vitamin D deficiency is common both before and after bariatric surgery, and is often difficult to treat, particularly with the more malabsorptive procedures. Additional research is needed to elucidate the complex and multifaceted factors underlying the association between low circulating 25-hydroxyvitamin D and obesity, and to identify optimal treatment approaches in obese individuals and in bariatric surgical patients both before and after surgery.

Impact of vitamin D metabolism on clinical epigenetics

The bioactive vitamin D (VD) metabolite, 1,25-dihydroxyvitamin D₃ regulates essential pathways of cellular metabolism and differentiation via its nuclear receptor (VDR). Molecular mechanisms which are known to play key roles in aging and cancer are mediated by complex processes involving epigenetic mechanisms contributing to efficiency of VD-activating CYP27A1 and CYP27B1 or inactivating CYP24 enzymes as well as VDR which binds to specific genomic sequences (VD response elements or VDREs). Activity of VDR can be modulated epigenetically by histone acetylation. It co-operates with other nuclear receptors which are influenced by histone acetyl transferases (HATs) as well as several types of histone deacetylases (HDACs). HDAC inhibitors (HDACi) and/or demethylating drugs may contribute to normalization of VD metabolism. Studies link VD signaling through the VDR directly to distinct molecular mechanisms of both HAT activity and the sirtuin class of HDACs (SIRT1) as well as the forkhead transcription factors thus contributing to elucidate complex epigenetic mechanisms for cancer preventive actions of VD.