Serum 25 hydroxyvitamin D concentrations in individuals over 80 years old and their correlations with musculoskeletal and health parameters

Brazilian older adults' vitamin D insufficiency and deficiency: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to identify the prevalence of vitamin D insufficiency and deficiency in older Brazilian adults. Design: Systematic review and meta-analysis. The search explored the MEDLINE, EMBASE, and LILACS platforms. Clinical and observational studies published before November 9, 2022, were included. The review was registered in PROSPERO No. 74,732 and evaluated using the adapted Loney scale. The search strategy identified 1,169 articles, of which 26 met the inclusion criteria, totaling 9,606 older adults. The vitamin D deficiency prevalence was 34.2% (95%CI: 25.0-44.6), and the insufficiency prevalence was 35.2% (95%CI: 31.0-39.5). The highest prevalence found was in the southern region (86.3% deficiency) and the southeast (51.4% insufficiency). Cross-sectional studies have shown a similar prevalence of vitamin D deficiency and insufficiency to the overall prevalence (34.2% and 33.7%). A statistically significant difference was found in the studies' risk of bias assessment (insufficiency subgroup). The results show a high prevalence of vitamin D insufficiency and deficiency in older Brazilian adults, pronounced even in places with higher incidences of sunlight.

High prevalence of low vitamin D status in the Czech Republic: a retrospective study of 119,925 participants

OBJECTIVES

Given the high worldwide prevalence of vitamin D deficiency and its role in numerous diseases affecting mortality and morbidity, this study seeks to determine the prevalence of low 25-hydroxyvitamin D levels in the Czech Republic, where population-level data are currently lacking.

STUDY DESIGN

This retrospective study utilized a large dataset to analyze 25-hydroxyvitamin D levels over an extended period.

METHODS

We analyzed data from 119,925 individuals aged 0-100 years categorizing them as sufficient (75-250 nmol/L), insufficient (50-75 nmol/L), or deficient (<50 nmol/L). We also examined levels of CRP, homocysteine, and their correlations with 25-hydroxyvitamin D levels across age groups. Age, sex, sampling month, sunlight exposure (monthly and annual), and influenza virus positivity were assessed for their relationship with the 25-hydroxyvitamin D levels.

RESULTS

The study found a high prevalence of 25-hydroxyvitamin D inadequacy, with sufficient levels observed in 65.6% of infants (0-12 months). The lowest prevalence of sufficiency was in the 6-15 years (19.2%) and 16-30 years (22.1%) groups. The highest deficiency prevalence was in the 91-100 years group (51.8%). 25-hydroxyvitamin D levels in all age groups and both sexes correlated with all selected parameters. Lower sun exposure, higher flu virus positivity, male gender, and elevated homocysteine and CRP levels were negatively correlated with 25-hydroxyvitamin D levels.

CONCLUSIONS

The prevalence of 25-hydroxyvitamin D inadequacy in the Czech Republic is high. It is advisable to consider testing, monitoring, and providing medical recommendations for vitamin D supplementation as part of health prevention strategies in the general population.

Vitamin D and hip protectors in osteosarcopenia: a combined hip fracture preventing approach

Osteosarcopenia is an emerging clinical condition highly prevalent in the older people. Affected subjects due to their intrinsic skeletal fragility and propensity to falls are at elevated risk of hip fractures which can increase morbidity and mortality. Strategies for attenuating the impact of predisposing factors on hip fractures are not yet well defined and should derive from multidisciplinary care and collaborations. Our aim was to narratively review available data on the preventive role of vitamin D and hip protectors on hip fractures in older patients with sarcopenia. Older subjects are at high risk of vitamin D deficiency and of falls due to several concomitant factors besides osteosarcopenia. Vitamin D protective actions against hip fractures may be mediated by both skeletal (increased mineralization) and extra-skeletal (reduced risk of falls) actions. Hip protectors may act downstream attenuating the effects of falls although their use is still not yet enough widespread due to the suboptimal compliance obtained by traditional hard devices. Concomitant use of vitamin D and hip protectors may represent an effective strategy in the prevention of hip fractures which need to be tested in ad hoc designed clinical trials.

Vitamin D and muscle health: insights from recent studies

PURPOSE OF REVIEW

The purpose of this review is to critically evaluate the effects of vitamin D on muscle mass and physical/muscle function in middle-aged and older adults, based on recent human studies, including cross-sectional, observational, and intervention studies. Vitamin D, beyond its well established role in bone health, has shown potential in influencing muscle physiology, making it a nutrient of interest in the context of sarcopenia and related chronic conditions.

RECENT FINDINGS

The review states how vitamin D affects muscle function, emphasizing its role in muscle cell proliferation, differentiation, and key signaling pathways. Additionally, the review of recent human studies revealed an inconsistent relationship between vitamin D and sarcopenia and related indices, with mixed results regarding muscle mass and strength. Variability in supplementation dose, duration, and baseline 25-hydroxyvitamin D levels may contribute to these inconsistencies.

SUMMARY

While animal studies indicate vitamin D's effectiveness in muscle growth, cross-sectional, observational, and intervention studies do not show clear benefits of maintaining efficient vitamin D levels on muscle mass or function in humans. Although vitamin D impacts muscle health, it is insufficient alone, emphasizing the need for a multifaceted approach to sarcopenia prevention and management.

The association of combined vitamin C and D deficiency with bone mineral density and vertebral fracture

PURPOSE

Both vitamin C and D deficiencies are extremely common in clinical practice, especially in elderly population. Unfortunately, the role of vitamin C deficiency in osteoporosis related consequences is often neglected. The aim of the present study is to analyse if combined vitamin C and D deficiency would have an association with bone mineral density (BMD) and osteoporotic vertebral fracture (OVF).

METHODS

Ninety-nine post-menopausal female patients admitted in the department of spine surgery of third affiliated hospital of Sun Yat-sen University were enrolled in the study. The participants were divided into four groups; vitamin D deficiency alone (comparator group), vitamin C deficiency alone and combined vitamin C and D deficiency as experimental group. The levels of vitamin C, vitamin D, calcium, phosphorous, BMD and condition of OVF were analysed.

RESULTS

There were statistically significant differences between the groups in terms of vitamin C and D levels. In terms of lumbar BMD, significant differences were observed between vitamin D deficiency alone and combined vitamin C and D deficiency. Only the combined vitamin C and D deficiency had a significant negative association with lumbar BMD and T-score. Similarly, combined vitamin C and D deficiency had a significant positive association with lumbar osteoporosis. None of the groups had any significant association with OVF. Combined vitamin C and D deficiency was found to be significantly associated with lower lumbar BMD and osteoporosis.

CONCLUSION

Combined vitamin C and D deficiency results in lower bone mineral density and higher risk of osteoporosis. We believe that existence of deficiencies of both vitamins could have a synergistic effect. Therefore, we recommend that vitamin C and D should be routinely measured in clinical practice.

Dietary Vitamin D Intake in Italian Subjects: Validation of a Frequency Food Questionnaire (FFQ)

Vitamin D plays a crucial role in calcium and phosphate metabolism, relating to bone health and preventing metabolic bone disorders such as rickets and osteomalacia. Vitamin D deficiency (serum 25-OH-D values <20 ng/mL or 50 nmol/L) is common also in Italian people; it is recommended to maintain levels above 30 ng/mL (75 nmol/L) in categories at risk. Supplementation and/or fortification with either ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) aimed to modify this condition have commonly been proposed. Studies about vitamin D intake are numerous in the literature but not adequately designed and are very often incomplete in Mediterranean Countries such as in the Italian population. On these bases, we performed a survey to validate a frequency food questionnaire (FFQ) specifically created to rapidly assess dietary vitamin D intake in Italian people. For this aim, the data of questionnaires were compared with results derived in the same population from a designed 14-day frequency food diary (FFD). Overall, a good correlation between FFQ and FFD was observed (r = 0.89, p < 0.001), both demonstrating a remarkably low vitamin D intake, irrespective of age and gender. Our data confirm that the vitamin D intake is very low in Italy, which likely contributes to hypovitaminosis D.