Vitamin D: Activities for Bone Health

Context: Despite growing interest in quantifying and correcting vitamin D inadequacy in basketball players, a critical synthesis of these data is yet to be performed to overcome the low generalizability of findings from individual studies. Objective: To provide a comprehensive analysis of data in basketball pertaining to (1) the prevalence of vitamin D inadequacy; (2) the effects of vitamin D supplementation on 25-hydroxyvitamin D [25(OH)D] concentration (and its association with body composition), bone health, and performance; and (3) crucial aspects that warrant further investigation. Data Sources: PubMed, MEDLINE, ERIC, Google Scholar, SCIndex, and ScienceDirect databases were searched. Study Selection: After screening, 15 studies were included in the systematic review and meta-analysis. Study Design: Systematic review and meta-analysis. Level of Evidence: Level 3. Data Extraction: The prevalence of vitamin D inadequacy, serum 25(OH)D, body composition, stress fractures, and physical performance were extracted. Results: The pooled prevalence of vitamin D inadequacy for 527 basketball players in 14 studies was 77% ( P < 0.001; 95% CI, 0.70-0.84). Supplementation with 4000 IU/d and 4000 IU/wk (absolute mean difference [AMD]: 25.39 nmol/L; P < 0.001; 95% CI, 13.44-37.33), as well as 10,000 IU/d (AMD: 100.01; P < 0.001; 95% CI, 70.39-129.63) vitamin D restored 25(OH)D to normal concentrations. Body composition data revealed inverse correlations between changes in serum 25(OH)D (from pre- to postsupplementation) and body fat ( r = −0.80; very large). Data concerning positive impacts of vitamin D supplementation on bone health and physical performance remain sparse. Conclusion: The high proportion of vitamin D inadequacy underscores the need to screen for serum 25(OH)D in basketball players. Although supplementation restored vitamin D sufficiency, the beneficial effects on bone health and physical performance remain sparse. Adiposity can modulate 25(OH)D response to supplementation.

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Vitamin K and D Supplementation and Bone Health in Chronic Kidney Disease—Apart or Together?

Nutrients ◽

10.3390/nu13030809 ◽

2021 ◽

Vol 13 (3) ◽

pp. 809

Author(s):

Marta Ziemińska ◽

Beata Sieklucka ◽

Krystyna Pawlak

Keyword(s):

Chronic Kidney Disease ◽

Vitamin D ◽

Kidney Disease ◽

Vitamin K ◽

Bone Health ◽

Clinical Evidence ◽

Mechanisms Of Action ◽

Preclinical Studies ◽

Normal Bone ◽

Combined Supplementation

Vitamin K (VK) and vitamin D (VD) deficiency/insufficiency is a common feature of chronic kidney disease (CKD), leading to impaired bone quality and a higher risk of fractures. CKD patients, with disturbances in VK and VD metabolism, do not have sufficient levels of these vitamins for maintaining normal bone formation and mineralization. So far, there has been no consensus on what serum VK and VD levels can be considered sufficient in this particular population. Moreover, there are no clear guidelines how supplementation of these vitamins should be carried out in the course of CKD. Based on the existing results of preclinical studies and clinical evidence, this review intends to discuss the effect of VK and VD on bone remodeling in CKD. Although the mechanisms of action and the effects of these vitamins on bone are distinct, we try to find evidence for synergy between them in relation to bone metabolism, to answer the question of whether combined supplementation of VK and VD will be more beneficial for bone health in the CKD population than administering each of these vitamins separately.

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