Efficacy of vitamin D supplementation in reducing body mass index and lipid profile in healthy young adults in Colombia: a pilot randomised controlled clinical trial.

The objective of the present study was to evaluate the efficacy of oral administration of vitamin D supplementation in reducing BMI and lipid profile in adolescents and young adults from a cohort in Bucaramanga, Colombia. One hundred and one young adults were randomly assigned to one of two doses of vitamin D [1000 international units (IU) or 200 IU] administered daily for 15 weeks. The primary outcomes were serum 25(OH)D levels, BMI and lipid profile. The secondary outcomes were waist-hip ratio, skinfolds and fasting blood glucose. We found a mean ± sd plasma concentration of 25-hydroxyvitamin D [25(OH)D] was 25⋅0 ± 7⋅0 ng/ml at baseline, and after 15 weeks, it increased to 31⋅0 ± 10⋅0 ng/ml in the participants who received a daily dose of 1000 IU, (P < 0⋅0001). For the participants in the control group (200 IU), it went from 26⋅0 ± 8⋅0 ng/ml to 29⋅0 ± 8⋅0 ng/ml (P = 0⋅002). There were no differences between groups in body mass index. There was a statistically significant decrease in LDL-cholesterol between the intervention group v. the control group (mean difference -11⋅50 mg/dl (95 % CI -21⋅86 to -1⋅15; P = 0⋅030). The conclusions of the present study were two different doses of vitamin D supplementation (200 IU v. 1000 IU) produced changes in serum 25(OH)D levels over 15 weeks of administration in healthy young adults. No significant changes were found in the body mass index when the effect of the treatments was compared. A significant reduction in LDL-cholesterol was found when comparing the two intervention groups. Trial registration: NCT04377386.

Efficacy of oral Vitamin D supplementation in reducing body mass index and lipid profile in adolescents and young adults in Colombia: A pilot clinical trial protocol nested in the SIMBA cohort.

BACKGROUND: In recent years, the role of vitamin D (VD) as a protective factor in cardiovascular disease has been recognized. Thus, there is a need to study the effect of vitamin D supplementation in the control of different cardiovascular risk factors and metabolic syndrome, especially in young populations where few studies have been conducted. METHODS: Pilot study of a randomized, parallel two-arm, triple-blind clinical controlled trial in 150 adolescents and young adults in the city of Bucaramanga-Colombia. The intervention group will receive 1000 IU of VD and the control group 200 IU of VD daily for 15 weeks. The main outcomes are: serum calcifediol levels (25(OH) D), body mass index and lipid profile; secondary outcomes are complementary to the previous ones (skin folds, waist-hip ratio). Other variables will be analyzed such as assessment of dietary intake, physical activity, sun exposure, cigarette and tobacco consumption and compliance with VD supplementation. DISCUSSION: This study is innovative since there is little evidence from clinical trials in adolescents and young adults; similar studies are not known in our context. The results of this study may facilitate the recommendation of oral vitamin D supplementation in the population of interest. In addition, it is a low-cost and easy-to-apply intervention that could contribute to the formulation and implementation of health policies. TRIAL REGISTRATION: NCT04377386.

WNT signaling modulates PD-L1 expression in the stem cell compartment of triple-negative breast cancer.

Triple-negative breast cancers (TNBCs) are characterized by a poor prognosis and lack of targeted treatments, and thus, new therapeutic strategies are urgently needed. Inhibitors against programmed death-1 (PD-1)/PD-1 ligand (PD-L1) have shown significant efficacy in various solid cancers, but their activity against TNBCs remains limited. Here, we report that human TNBCs molecularly stratified for high levels of PD-L1 (PD-L1High) showed significantly enriched expression of immune and cancer stemness pathways compared with those with low PD-L1 expression (PD-L1Low). In addition, the PD-L1High cases were significantly associated with a high stemness score (SSHigh) signature. TNBC cell lines gated for aldehyde dehydrogenase (ALDH) and CD44 stemness markers exhibited increased levels of PD-L1 versus their ALDH-negative and CD44Low counterparts, and PD-L1High cells generated significantly more mammospheres than PD-L1Low cells. Murine mammary SCA-1-positive tumor cells with PD-L1High expression generated tumors in vivo with higher efficacy than PD-L1Low cells. Furthermore, treatment of TNBC cells with selective WNT inhibitors or activators downregulated or upregulated PD-L1 expression, respectively, implying a functional cross-talk between WNT activity and PD-L1 expression. Remarkably, human TNBC samples contained tumor elements co-expressing PD-L1 with ALDH1A1 and/or CD44v6. Additionally, both PD-L1-/SCA1-positive and ALDH1A1-positive tumor elements were found in close contact with CD3-, and PD-1-positive T cells in murine and human tumor samples. Overall, our study suggests that PD-L1-positive tumor elements with a stemness phenotype may participate in the complex dynamics of TNBC-related immune evasion, which might be targeted through WNT signaling inhibition.