Regular Consumption of Both Vitamin D– and Calcium- and Vitamin D–Fortified Yogurt Drink Is Equally Accompanied by Lowered Blood Lipoprotein (a) and Elevated Apoprotein A1 in Subjects with Type 2 Diabetes: A Randomized Clinical Trial

Fortification of Staple Foods for Household Use with Vitamin D: An Overview of Systematic Reviews

Vitamin D deficiency is a global public health concern with significant implications for bone health and chronic disease prevention. Our aim was to summarize the evidence from Cochrane and other systematic reviews evaluating the benefits or harms of vitamin D fortification of staple foods for household use. In April 2023, we systematically searched Ovid MEDLINE, Embase, Epistemonikos and the Cochrane Database of Systematic Reviews for systematic reviews investigating the effects of vitamin D fortification of food in general populations of any age. We used Cochrane methodology and assessed the methodological quality of included studies using AMSTAR (A MeaSurement Tool to Assess Systematic Reviews). We assessed the degree of overlap among reviews. All outcomes included in systematic reviews were assessed. The protocol is registered in PROSPERO (registration number: CRD42023420991). We included 27 systematic reviews out of 5028 records for analysis. Overall, 11 out of 12 systematic reviews calculating pooled estimates reported a significant increase in serum 25(OH)D concentrations. The mean change in serum 25(OH)D concentrations per additional 100 units of vitamin D ranged from 0.7 to 10.8 nmol/L. Fortification of food with vitamin D showed a reduction in the prevalence of vitamin D deficiency based on high-certainty evidence. Parathormone (PTH) levels were described to decrease, bone mineral density to increase, while the effects on other bone turnover markers were inconsistent. Fortification did not significantly impact most anthropometric parameters, but it seemed to positively influence lipid profiles. In summary, fortification of food with vitamin D results in a reduction of vitamin D deficiency and might increase serum 25(OH)D concentrations, to varying extents depending on the fortified vehicle and population characteristics. Additionally, fortification may have a positive impact on bone turnover and lipid metabolism but may only have a limited effect on anthropometric parameters.

Modulation of cardiometabolic risk and CardioRenal syndrome by oral vitamin D3 supplementation in Black and White Southern Sahara residents with chronic kidney disease Stage 3: focus on racial and ethnic disparities

OBJECTIVES

Several studies have shown that cholecalciferol supplementation (25OHD-S) in chronic kidney disease (CKD) improves kidney injury by reducing fibrosis-related vascular calcification and declining apoptosis-linked nephron damage.

METHODS

The oral 25OHD-S was evaluated in 60,000 IU/month/36 weeks versus in 2000 IU/d/24 weeks in CKD Stage 3 with serum 25OHD level < 20 ng/mL. The study was undertaken on 156 black subjects and 150 white subjects Southern Sahara (SS). All biomarkers of cardiometabolic (CMet) and cardiorenal (CRenal) syndrome, Renin-angiotensin-aldosterone system (RAAS) profile, secondary hyperparathyroidism (SHPT), N-terminal pro B-type natriuretic peptide (NT-proBNP), Troponin T (cTnT) and atherogenicity risk were assessed by biochemical methods. Estimate glomerular filtration rate (eGFR) by chronic CKD-EPI equation formula. Total serum vitamin D by liquid chromatography-tandem mass spectrometry (MS).

RESULTS

Vitamin D deficiency alters in the same manner CMet, CRenal, and others biomarkers in both groups SS; however, these disorders are more acute in blacks compared to whites SS. Oral 25OHD-S a highlighted improvement of eGFR drop, SHPT decrease, decline proteinuria, and cardiac failure risk (NT-proBNP and cTnT) attenuation. Concomitantly, 25OHD-S normalizes Renin, Aldosterone, and Angiotensin System (RAAS) activity. Nevertheless, homocysteine and Lp (a) do not modulate by 25OHD-S.

CONCLUSIONS

The oral vitamin D3 supplementation, according the dose, and the treatment duration does not like in black-skinned people versus to white-skinned inhabitants, while the 02 groups are native to the same Saharan environment. It emerge that a high intermittent dose through an extensive supplementation (60,000 IU/36 weeks) was more effective in black subjects. At opposite, a lower dose during a short period supplementation is sufficient (2000 IU/24 weeks) in white subjects.

Oral Cholecalciferol Supplementation in Sahara Black People with Chronic Kidney Disease Modulates Cytokine Storm, Oxidative Stress Damage and Athero-Thromboembolic Risk

The 25-hydroxyvitamin D3 (25OHD3) deficiency in chronic kidney disease (CKD) is associated with immune system dysfunction (pro-inflammatory cytokines storm) through macrophages renal infiltration, oxidative stress (OxS) damage and athero-thromboembolic risk. Conversely, cholecalciferol supplementation (25OHD-S) prevents kidney fibrosis by inhibition of vascular calcification and nephrotic apoptosis (nephrons reduction). The objective of this study was to investigate the pleiotropic effects of 25OHD-S on immunomodulation, antioxidant status and in protecting against thromboembolic events in deficiency CKD Black and White individuals living in the Southern Sahara (SS). The oral 25OHD-S was evaluated in 60,000 IU/month/36 weeks versus in 2000 IU/day/24 weeks in Black (n = 156) and White (n = 150). Total serum vitamin D was determined by liquid chromatography-tandem mass spectrometry. All biomarkers of pro-inflammatory cytokines (PIC) were assessed by ELISA tests. OxS markers were assessed by Randox kits. Homocysteine and lipoproteine (a) were evaluated by biochemical methods as biomarkers of atherothromboembolic risk. All statistical analyses were performed with Student’s t-test and one-way ANOVA. The Pearson test was used to calculate the correlation coefficient. The means will be significantly different at a level of p value < 0.05. Multiple logistic regressions were performed using Epi-info and Statview software. Vitamin D deficiency alters the PIC profile, OxS damage and atherothrombogenic biomarkers in both SS groups in the same manner; however, these disorders are more acute in Black compared to White SS individuals. The results showed that the serum 25OHD3 concentrations became normal (>75 nmol/L or >30 ng/mL) in the two groups. We have shown that the dose and duration of 25OHD-S treatment are not similar in Black SS residents compared to White SS subjects, whilst the same inhabit the south Sahara environment. It appears that a high dose intermittent over a long period (D60: 36 weeks) was more efficient in Black people; while a lower dose for a short time is sufficient (D2: 24 weeks) in their White counterparts. The oral 25OHD-S attenuates PIC overproduction and OxS damage, but does not reduce athero-thromboembolic risk, particularly in Black SS residents.

Effects of 12-week, non-energy-restricted dietary intervention with conventional yogurt οn appetite hormone responses of type 2 diabetic patients

Hunger-reducing effects and beneficial changes in gastrointestinal hormones have been reported, in overweight/obese individuals consuming dairy while yogurt takes pride of place due to its unique structure and composition. Although the contribution of yogurt to metabolic regulation has received growing attention, the research studies which examine its role on appetite are limited, especially regarding type 2 diabetes mellitus (T2DM) patients. The aim of the present study was to investigate the effects of non-fat, conventional yogurt consumption on appetite hormone responses of T2DM patients following a non-energy-restricted diet. Overweight subjects participated in a 12-week dietary intervention including 2 meals/day (2 × 200 g) of yogurt. At the beginning and the end of the intervention, a mixed meal tolerance test assessing the postprandial response of glucose, insulin, ghrelin, glucagon-like peptide-1 (GLP-1), and peptide-YY (PYY) was performed. Subjective appetite ratings were also evaluated. Area under the curve for glucose, insulin, ghrelin, GLP-1, and PYY responses did not differ after the 12-week intervention with yogurt (p > .05) as well as for subjective appetite ratings (p > .05). No significant differences were indicated at specific time points in any of the examined parameters. Regular consumption of non-fat, conventional yogurt for 12-week duration does not affect appetite hormone responses in overweight patients with T2DM following a non-energy-restricted diet.

Contribution of vitamin D status as a determinant of cardiometabolic risk factors: a structural equation model, National Food and Nutrition Surveillance

Background

Structural equation modeling (SEM) is a method used to evaluate linear causal relationships among variables. This study aimed to investigate the direct and indirect effects of serum 25(OH) D on certain cardiovascular risk factors using SEM.

Methods

An analytical cross-sectional study was conducted in six provinces of Iran. Subjects (n = 922), aged 19–65 years, were selected from National Food and Nutrition Surveillance. The assessments were sun-exposure behavior, anthropometric and biochemical measurements. A series of SEM models were tested and the model with the best fit indices was considered for use in the structural part of the model. Based on the literature review of previous theoretical models and supporting bivariate analyses, an overall SEM examined direct or indirect associations among observed and latent variables. We put the demographic, duration of sun exposure, anthropometric and metabolic variables in our model.

Results

The paths between serum 25(OH) D and BMI were inverse and statistically significant, whereas age showed a positive association with BMI (B = 0.06, p < 0.001), both direct (st. effect = 0.11, p = 0.01) and indirect via vitamin D (st. effect = − 0.02, p = 0.01). The results confirmed that serum 25(OH) D concentration is a predictor for latent variable of lipid profile (B = − 0.13, p = 0.01) both through direct (p = 0.02) and indirect effects via BMI (p = 0.01).

Conclusion

Serum 25(OH) D concentration is a predictor of BMI and also a latent variable of lipid profile via direct and indirect effects. It can also attenuate the harmful effect of age on BMI and lipid profile particularly in women.

Can vitamin D be considered an adiponectin secretagogue? A systematic review and meta-analysis

There is some evidence for ameliorating effect of vitamin D on glycemic and lipidemic status which are likely to be mediated through other molecules including adiponectin. However, the overall results have been controversial. This study was conducted to evaluate the effect of vitamin D supplementation on serum adiponectin concentration. MEDLINE, PubMed, Embase, Cochrane Library, and Google Scholar were searched and 402 studies were found in a preliminary search. After screening of titles and abstracts nine studies were selected. Pooled data showed no significant effect on adiponectin concentrations (mean difference (MD) 0.37, 95 % CI: -0.1 to 0.87). However, there was a significant effect in a subgroup of participants who had diabetes (MD: 0.03, 95 % CI: 0.00 to 0.05, p = 0.029). The treatment effect on adiponectin concentrations was significant in those trials that used supplementation on a daily basis (MD: 0.03, 95 % CI: 0.00 to 0.05, p = 0.028) and vitamin D plus calcium (MD: 0.04, 95 % CI: 0.01 to 0.07, p = 0.014). The meta-regression revealed a significant association between BMI and age of participants at baseline and the treatment effect (B, -0.144, 95 % CI: -0.276 to -0.011, p = 0.033 and B, -0.043, 95 % CI: -0.075 to -0.012, p = 0.006). The results of this meta-analysis study indicates that vitamin D may be considered an adiponectin secretagogue in subjects with diabetes and this effect may be potentiated if vitamin D intake is on daily basis and in combination with calcium but can be weakened by increasing BMI.

Probiotic Yogurt Fortified with Vitamin D Can Improve Glycemic Status in Non-Alcoholic Fatty Liver Disease Patients: a Randomized Clinical Trial

Non-alcoholic fatty liver disease (NAFLD) is a significant public health problem globally and the most notable chronic liver disease in Asian countries. Various dietary supplements have been assessed as potential methods to alleviate the metabolic damages related to NAFLD, but the results of these works have been equivocal. This study aimed to evaluate the effects of probiotic yogurt fortified with vitamin D (Pro-YFD) on glycemic and anthropometric indices in patients with NAFLD. One hundred and four NAFLD patients of both sexes were randomly allocated to 2 groups: group A (Pro-YFD) and group B (unfortified yogurt). The intervention period was 3 months. Fasting blood samples were obtained for measuring fasting blood sugar (FBS) and insulin level. Food intake was measured using a validated food frequency questionnaire. Body composition was estimated by bio-impedance. Eighty-eight patients completed the study. The mean serum level of 25(OH)D₃ was elevated significantly (p < 0.001), while insulin level decreased significantly (p < 0.003) in group A at the end of the study. FBS levels showed no significant differences between the groups at the end of the trial. Also, there were no significant changes in diet caloric intake, physical activity, or anthropometric indices in the 2 groups during the interventions. Pro-YFD in the diets of patients with NAFLD may attenuate insulin resistance and improve serum level of 25(OH)D₃.

A systematic review and meta-analysis of the effect of Vitamin D-fortified food on glycemic indices

Some reports indicated that Vitamin D may improve glycaemia indices in diabetic patients. The aim of this systematic and meta-analysis was to evaluate effects of Vitamin D fortification on indices of glycemic control. Six databases (PubMed/Medline, ISI Web of Knowledge, Cochrane Library, Science Direct, Scopus, and Google Scholar) were searched, for randomized controlled trials that were published up to September 2018 and that compared the effect of Vitamin D-fortified food versus regular diet in relation to glycemic control. Of the 4,379 studies originally found, 11 articles remained to be assessed for meta-analysis. Vitamin D fortification was associated with a significant improvement in fasting serum glucose (mean difference [MD]: -2.772; 95% confidence interval [CI]: -5.435 to -0.109) and fasting serum insulin (MD: -2.937; 95% CI: -4.695 to -1.178) in patients with Type 2 diabetes mellitus. A diet with food enriched with Vitamin D was associated with a significant improvement in homeostatic model assessment of insulin resistance (MD: -1.608; 95% CI: -3.138 to -0.079) but was not associated with a significant reduction in hemoglobin A1C (MD: 0.034; 95% CI: -0.655 to 0.069). This meta-analysis indicates that Vitamin D fortification improves indices of glycemic control. Hence, food fortified with Vitamin D may be of potential therapeutic value in diabetic patients, as an adjuvant therapy.

Vitamin D-fortified cooking oil is an effective way to improve vitamin D status: an institutional efficacy trial

PURPOSE

High prevalence of vitamin D deficiency (VDD) justifies a cost-effective and sustainable strategy to combat VDD in the community. This study was undertaken for the first time to evaluate the efficacy of daily consumption of vitamin D fortified sunflower oil with a meal.

METHODS

This single-blind trial was conducted in two separate institutions: one as intervention (D-fortified sunflower oil) group (DO, n₁ = 39) and the other as control (unfortified sunflower oil) group (SO, n₂ = 33). Participants consumed their lunches cooked either with D-fortified or unfortified cooking sunflower oil (500 IU/30 g) for 12 weeks. Dietary, anthropometric and biochemical assessments were done for all participants before and after the intervention.

RESULTS

A total of 65 subjects from both sexes aged 32.5 ± 4 years completed the intervention period. Serum 25(OH)D showed a significant increase in DO and a decrease in SO group (8.8 ± 9.3 vs. - 7.4 ± 6.4 ng/mL, p < 0.001). The rise in serum 25(OH)D in DO group was accompanied by a significant decrease in iPTH (DO: - 10.2 ± 29.4 vs. SO: + 9.2 ± 29.5 pg/mL; p = 0.009). A significant reduction in weight (p = 0.004), BMI (p = 0.029), waist girth (p < 0.001), serum total cholesterol (p = 0.0290) and LDL-C (p = 0.010) was observed in DO, as compared with SO group.

CONCLUSIONS

Cooking oil can be considered as an efficacious vehicle for mass fortification program to combat VDD. The improvement of vitamin D status may bring about betterment of certain cardiometabolic risk factors.

REGISTRATION NUMBER

Clinicaltrials.gov: NCT03826654.

Daily consumption of fruit-flavored yoghurt enriched with vitamins B contributes to lower energy intake and body weight reduction, in type 2 diabetic patients: a randomized clinical trial

Fruit-yoghurt enriched with vitamins B promotes body weight reduction and improves vitamin B status and homocysteine levels in T2DM patients.

Sex-specific expression of apolipoprotein levels following replenishment of vitamin D

Numerous studies have been done to establish the relationship between vitamin D and lipids, yet a definitive causal link is not found. This interventional study aims to evaluate and compare levels of apolipoproteins among vitamin D deficient subjects at baseline and after they achieved full vitamin D status correction.120 Saudi adults with vitamin D deficiency [25(OH)D < 50nmol/l] were recruited and given 50,000IU cholecalciferol weekly for first 2 months, then twice a month for next 2 months, followed by daily 1000IU until month 6. Blood samples were taken at baseline and after 6 months. Serum 25(OH)D, lipid profile and apolipoproteins (A1, A2, B, C1, C2, C3, E and H) were analyzed using commercially available kits. Overall, serum 25(OH)D increased significantly(63.3 ± 16.5nmol/l at end of study vs. 32.5 ± 10.8 at baseline; p < 0.0001). In parallel, a significant increase in apolipoproteins C1, C2, C3 and E (all p-values < 0.01) and a significant decrease in apolipoprotein B (p = 0.02) was observed. Following, stratification according to sex, apolipoproteins C2 and C3 significantly increased only in males (p-values < 0.01) while apolipoprotein C1 significantly increased only in females (p < 0.01). In addition, apolipoprotein B significantly decreased only in females (p = 0.002). These results suggests role of vitamin D in modulation of circulating levels of lipoproteins. The sexual dimorphism observed in circulating levels of measured apolipoproteins following vitamin D correction may explain, in part, known sexual disparity in the events of cardiometabolic health.

Efficacy of Vitamin D interventional strategies in saudi children and adults

Despite the amount of sunshine in Saudi Arabia, vitamin D (25(OH)D) deficiency is highly prevalent among Saudis. Several strategies are known to improve 25(OH)D status. The aim of this study was to evaluate the efficacy of different interventional strategies in improving 25(OH)D status in Saudi children and adults. This interventional study was undertaken among 593 out of 1152 Saudi subjects [530 students (aged 13-17 years) and 63 teachers (aged 26-46 years)] over a 6-month period from different secondary schools in Riyadh, Saudi Arabia. 25(OH)D status was taken at baseline and after 6 months post interventions. Subjects were divided into 3 groups and requested to implement different vitamin D correction schemes: sun-exposure, vitamin D-fortified milk consumption, and oral vitamin D supplementation (1000IU/day). Follow-up results revealed that all correction strategies used could decrease the deficiency of serum 25(OH)D with different potencies, with the highest positive percentage change observed in oral supplementation in both adults and children (11% men, 17% women, 16% boys and 8% girls). The oral vitamin D supplementation strategy also showed significant positive associations between delta (Δ) changes and HDL-cholesterol in both adults and children. In conclusion, oral vitamin D supplementation was the most effective strategy in improving vitamin D status in Saudi adults and children than sunlight exposure or consumption of vitamin D-fortified dairy products.

Vitamin D supplementation and lipoprotein metabolism: A randomized controlled trial

BACKGROUND

Vitamin D deficiency is associated with an unfavorable lipid profile, but whether and how vitamin D supplementation affects lipid metabolism is unclear.

OBJECTIVE

To examine the effects of vitamin D supplementation on lipid and lipoprotein parameters.

METHODS

This is a post hoc analysis of the single-center, double-blind, randomized, placebo-controlled Styrian Vitamin D Hypertension Trial (2011-2014). Two hundred individuals with arterial hypertension and 25-hydroxyvitamin D concentrations of <75 nmol/L were randomized to 2800 IU of vitamin D daily or placebo for 8 weeks.

RESULTS

One hundred sixty-three participants (62.2 [53.1-68.4] years of age; 46% women) had available lipid data and were included in this analysis. Vitamin D supplementation significantly increased total cholesterol, triglycerides, very-low-density lipoprotein (VLDL) triglycerides, low-density lipoprotein (LDL) triglycerides, high-density lipoprotein (HDL) triglycerides, apolipoprotein B (ApoB), LDL-ApoB, ApoCII, ApoCIII, phospholipids, and ApoE (P < .05 for all). Except for ApoCII and ApoCIII and HDL-triglycerides, all other treatment effects remained statistically significant after adjustment for multiple testing with the Benjamini and Hochberg false discovery rate method. There was a nonsignificant increase in LDL cholesterol. Furthermore, no significant effects were seen on free fatty acids, lipoprotein (a), ApoAI, ApoAII, VLDL cholesterol, VLDL-ApoB, HDL cholesterol, LDL diameter, and VLDL diameter.

CONCLUSIONS

The effects of vitamin D on lipid metabolism are potentially unfavorable. They require further investigation in view of the wide use of vitamin D testing and treatment.

Non-musculoskeletal benefits of vitamin D

The aim of this study is to determine and critically evaluate the plausible relationships of vitamin D with extra-skeletal tissues in humans. Severe vitamin D deficiency results in rickets in children and osteomalacia in adults; these beneficial effects in the musculoskeletal system and certain physiological functions are well understood. Nevertheless, mounting reports support additional beneficial effects of vitamin D, outside the musculoskeletal system. This review explores the recent advances in knowledge about the non-skeletal effects of vitamin D. Peer-reviewed papers were extracted from research databases using key words, to assess correlations between vitamin D and extra-skeletal diseases and conditions. As per the guidelines of the Preferred Reporting Items for Systematic Reviews (PRISMA); general interpretations of results are included; taking into consideration the broader evidence and implications. This review summarizes current knowledge of the effects of vitamin D status on extra-skeletal tissues with special attention given to relationships between vitamin D status and various diseases commonly affecting adults; the effects of intervention with vitamin D and exposure to sunlight. Evidence suggests that vitamin D facilitates the regulation of blood pressure; and cardiac; endothelial; and smooth muscle cell functions; playing an important role in cardiovascular protection. In addition; 1,25(OH)₂D improves immunity; subdues inflammation; and reduces the incidence and severity of common cancers; autoimmune diseases and infectious diseases. Almost all adequately powered; epidemiological and biological studies that use; adequate doses of vitamin D supplementation in D-deficient populations have reported favorable outcomes. These studies have concluded that optimizing 25(OH)D status improves the functionality of bodily systems; reduces comorbidities; improves the quality of life; and increases survival. Although accumulating evidence supports biological associations of vitamin D sufficiency with improved physical and mental functions; no definitive evidence exists from well-designed; statistically powered; randomized controlled clinical trials. Nevertheless, most studies point to significant protective effects of vitamin D in humans when the minimum 25(OH)D serum level exceeds 30ng/mL and is maintained throughout the year.

Dietary Strategies and Novel Pharmaceutical Approaches Targeting Serum ApoA-I Metabolism: A Systematic Overview

The incidence of CHD is still increasing, which underscores the need for new preventive and therapeutic approaches to decrease CHD risk. In this respect, increasing apoA-I concentrations may be a promising approach, especially through increasing apoA-I synthesis. This review first provides insight into current knowledge on apoA-I production, clearance, and degradation, followed by a systematic review of dietary and novel pharmacological approaches to target apoA-I metabolism. For this, a systematic search was performed to identify randomized controlled intervention studies that examined effects of whole foods and (non)nutrients on apoA-I metabolism. In addition, novel pharmacological approaches were searched for, which were specifically developed to target apoA-I metabolism. We conclude that both dietary components and pharmacological approaches can be used to increase apoA-I concentrations or functionality. For the dietary components in particular, more knowledge about the underlying mechanisms is necessary, as increasing apoA-I per se does not necessarily translate into a reduced CHD risk.

Vitamin D status and cardiometabolic risk factors across latitudinal gradient in Iranian adults: National food and nutrition surveillance

BACKGROUND

This study aimed to evaluate the vitamin D status in an adult population across latitudinal gradient and to investigate its possible associations with certain cardiometabolic risk factors.

METHODS

A total of 1406 healthy subjects aged 19-60 years were randomly selected from six regions of Iran across latitudinal gradient from 29° N to 37.5° N. Anthropometric and biochemical assessments were performed. The combination of high body mass index (>25 kg/m²), low high-density lipoprotein cholesterol (< 40 mg/dl in males and < 50 mg/dl in females) and high triglycerides (> 150 mg/dl) was defined as cardiometabolic risk factors.

RESULTS

The mean concentration of serum 25-hydroxycalciferol (25(OH)D) was 26.8±17.7 nmol/l. There were no significant differences in the mean serum 25(OH)D levels among different latitudes. Undesirable vitamin D status (deficiency and insufficiency) was found in 90.7% of the subjects. After adjustment for age and gender, the association between weight status and serum 25(OH)D was significant ( p< 0.04, odds ratio:1.49; confidence interval: 1.01-2.19). The prevalence of cardiometabolic risk factors among the subjects with serum 25(OH)D less than 27.5 nmol/l was significantly higher than those with serum calcidiol concentrations above 27.5 nmol/l (13.3% vs. 10.0%, p = 0.033).

CONCLUSION

Undesirable vitamin D status is highly prevalent among Iranian adults of both sexes irrespective of latitude and even in sunny regions. The occurrence of cardiometabolic risk factors was significantly higher in those subjects with circulating calcidiol concentrations below 27.5 nmol/l.

Effects of 12-month, 2000IU/day vitamin D supplementation on treatment naïve and vitamin D deficient Saudi type 2 diabetic patients

Objectives:

To determine whether 12-month, 2000IU/day vitamin D supplementation cardiometabolically improves treatment naïve type 2 diabetes mellitus (T2DM) Saudi patients with vitamin D deficiency.

Methods:

This 12-month interventional study was conducted at primary health centers in 5 different residential areas in Riyadh, Saudi Arabia between January 2013 and January 2014. Forty-five Saudi T2DM patients were enrolled. Baseline anthropometrics, glycemic, and lipid profiles were measured and repeated after 6 and 12 months. All subjects were provided with 2000IU vitamin D supplements for one year.

Results:

Vitamin D deficiency at baseline was 46.7%, 31.8% after 6 months, and 35.6% after 12 months, indicating an overall improvement in the vitamin D status in the entire cohort. Insulin and homeostatic model assessment-insulin resistance (HOMA-IR) after 12 months were significantly lower than a 6 months (p<0.05), but comparable to baseline values. Mean levels of triglycerides increased overtime from baseline (1.9±0.01 mmol/l) to 12 months (2.1±0.2 mmol). This modest increase in serum triglycerides was parallel to the insignificant decrease in circulating high-density lipoprotein -cholesterol levels.

Conclusion:

Twelve-month vitamin D supplementation of 2000IU per day in a cohort of treatment naïve Saudi patients with T2DM resulted in improvement of several cardiometabolic parameters including systolic blood pressure, insulin, and HOMA-IR. Further studies that include a placebo group are suggested to reinforce findings.

The Potential Role of Yogurt in Weight Management and Prevention of Type 2 Diabetes

Yogurt is a semisolid fermented milk product that originated centuries ago and is viewed as an essential food and important source of nutrients in the diet of humans. Over the last 30 years, overweight and obesity have become characteristic of Western and developing countries, which has led to deleterious health outcomes, including cardiovascular disease, type 2 diabetes, hypertension, and other chronic conditions. Recent epidemiological and clinical evidence suggests that yogurt is involved in the control of body weight and energy homeostasis and may play a role in reducing the risk for type 2 diabetes partly via the replacement of less healthy foods in the diet, its food matrix, the effect of specific nutrients such as calcium and protein on appetite control and glycemia, and alteration in gut microbiota. This review will discuss the specific properties that make yogurt a unique food among the dairy products, epidemiological and clinical evidence supporting yogurt's role in body weight, energy balance, and type 2 diabetes, including its potential mechanisms of action and gaps that need to be explored. Key teaching points • Several epidemiological and clinical studies have suggested a beneficial effect of yogurt consumption in the control of body weight and energy homeostasis, although this remains controversial. • Yogurt possesses unique properties, including its nutritional composition; lactic acid bacteria, which may affect gut microbiota; and food matrix, which may have a potential role in appetite and glycemic control. • Potential mechanisms of action of yogurt include an increase in body fat loss, decrease in food intake and increase in satiety, decrease in glycemic and insulin response, altered gut hormone response, replacement of less healthy foods, and altered gut microbiota. • The relative energy and nutrient content and contribution of a standard portion of yogurt to the overall diet suggest that the percentage daily intake of these nutrients largely contributes to nutrient requirements and provides a strong contribution to the regulation of energy metabolism.

Vitamin D-Fortified Bread Is as Effective as Supplement in Improving Vitamin D Status: A Randomized Clinical Trial

CONTEXT

Bread can potentially be a suitable vehicle for fortification with vitamin D.

OBJECTIVE

This study was undertaken to evaluate the following: 1) the bioavailability of vitamin D from the fortified Iranian bread and 2) the possible effects of daily consumption of the fortified bread on certain health aspects.

DESIGN, SETTING, AND PARTICIPANTS

This was a randomized, double-blind, placebo-controlled trial conducted over 8 weeks in 90 healthy subjects aged 20-60 years.

INTERVENTION

Subjects were randomly allocated to one of three groups: 1) fortified bread (FP; 50 g bread fortified with 25 μg vitamin D3 plus placebo daily; n = 30); 2) supplement (SP; 50 g plain bread plus 25 μg vitamin D supplement daily; n = 30); and 3) control (CP; 50 g plain bread plus placebo daily; n = 30).

OUTCOME MEASURES

Initial and final anthropometric and biochemical assessments were performed.

RESULTS

The within-group changes of serum 25-hydroxyvitamin D concentrations were 39.0 ± 22.6 (P < .001), 28.9 ± 31.2 (P < .001), and -9.2 ± 12.3 nmol/L in the FP, SP, and CP groups, respectively. Only in FP and SP groups, serum intact PTH concentrations decreased approximately 13.5% and 14.5%, respectively. Visceral fat also showed a significant decrement in FP (-1.05% ± 1.4%; P ≤ .001) and SP (-0.96% ± 1.7%; P = .006). Serum low-density lipoprotein cholesterol concentration showed a within-group reduction in FP (-10.4 ± 11.2 mg/dL; P < .001) and an insignificant decrement in SP (-6.6 ± 20.2 mg/dL; P = .083). Serum high-density lipoprotein increased in both vitamin D-supplemented groups (FP: 9.7 ± 7.6 vs SP: 5.7 ± 6.7 mg/dL; P < .001).

CONCLUSION

Vitamin D-fortified bread could be potentially effective in raising circulating 25-hydroxyvitamin D levels of the population to nearly adequate levels.

Oxidative stress, type 2 diabetes and vitamin D: past, present and future

Oxidative stress refers to an imbalance between potentially harmful free radicals and the body's mechanisms to efficiently detoxify them in favor of the free radicals. Consequently, excess free radicals can attack and damage a wide range of biomolecules including proteins, lipids and nucleic acids. Antioxidant mechanisms of the body are under the influence of genetic and environmental (including dietary) factors. Diabetes is one of the most common metabolic disorders around the world. A huge body of evidence indicates a role for oxidative stress in development of many human diseases including diabetes. In this article, the latest information on the possible links of oxidative stress with diabetes development, control and complications as well as the newest results of antioxidant supplementation trials is reviewed. In addition, the possible role of vitamin D, as a newly recognized antioxidant in diabetes is discussed. Finally, concluding remarks on pivotal issues and future studies are presented.

Dairy foods and dairy proteins in the management of type 2 diabetes: a systematic review of the clinical evidence

Type 2 diabetes mellitus (T2DM) is a growing public health concern affecting hundreds of millions of people worldwide and costing the global economy hundreds of billions of dollars annually. This chronic disease damages the blood vessels and increases the risk of other cardiometabolic ailments such as cardiovascular disease and stroke. If left unmanaged it can also lead to nerve damage, kidney damage, blindness, and amputation. For the most part, many of these symptoms can be prevented or reduced through simple dietary modifications and proper nutrition. Therefore, identifying relatively inexpensive and easily implementable dietary modifications for the prevention and management of T2DM is of considerable value to human health and healthcare modalities around the globe. Protein-rich dairy products have consistently been shown in epidemiologic studies to be beneficial for reducing the risk of developing T2DM. The clinical evidence regarding both dairy foods and dairy proteins (i.e., casein and whey protein) have shown promise for improving insulin secretion in individuals with T2DM. However, the clinical research on dairy protein supplementation in subjects with T2DM has been limited to acute studies. These studies have been mostly descriptive and have not been focused on important T2DM endpoints such as prevention, management, or treatment. Long-term studies are clearly needed to help researchers and medical professionals better understand the effects of consistent dairy protein intake on the metabolic health of humans with T2DM.