Meta-Analysis of European Clinical Trials Characterizing the Healthy-Adult Serum 25-hydroxyvitamin D Response to Vitamin D Supplementation

Abstract

To obtain reliable data that allow health authorities to re-evaluate recommendations for oral vitamin D uptake, we conducted a meta-analysis to investigate the impact of supplementation on serum 25-hydroxyvitamin D (25(OH)D) levels in healthy adults in Europe. Of the publications identified (n = 4005) in our literature search (PUBMED, through 2 January 2022), 49 primary studies (7320 subjects, 73 study arms) were eligible for inclusion in our meta-analysis. The risk of bias was assessed using the Cochrane RoB tool based on seven categories, according to which each study is rated using three grades, and overall was rated as rather low. The median duration of intervention was 136.78 days (range, 1088 days); the mean weighted baseline 25(OH)D concentration and mean age were 33.01 vs. 33.84 nmol/L and 46.8 vs. 44.8 years in the vitamin D and placebo groups, respectively. Using random-effects models, 25(OH)D levels were increased by 36.28 nmol/L (95% CI 31.97–40.59) in the vitamin D group compared to the placebo, with a relative serum increment of 1.77 nmol/L per 2.5 μg of vitamin D daily. Notably, the relative serum 25(OH)D increment was affected by various factors, including the dosage and baseline serum 25(OH)D concentration, decreasing with increasing vitamin D doses and with increasing baseline serum levels. We estimate that supplementation in all healthy adults in Europe with appr. 25 μg of vitamin D (1000 IU) daily would raise serum 25(OH)D levels in 95% of the population to ≥50 nmol/L. Our work provides health authorities with reliable data that can help to re-evaluate recommendations for oral vitamin D supplementation.

Sex Differences under Vitamin D Supplementation in an Animal Model of Progressive Multiple Sclerosis

“…One recent recommendation for VD supplementation for all healthy adults in Europe is approximately 1000 IU daily. This would raise the VD serum levels in 95% of the population to >50 nmol/L [ 34 ]. In another systematic review, data confirmed that keeping the VD serum concentrations above 50 ng/mL (125 nmol/L) reduces the risk from community outbreaks, sepsis and autoimmune disorders [ 35 ].…”

“…These differences in dosage recommendations highlight the need among both healthy and diseased human beings for monitoring VD serum levels and correspondingly adjusting VD dosage. Only when reaching an individual proper dose of VD can effectiveness be ensured and any adverse effects due to overdosing be avoided [ 34 ]. Besides finding the correct dosage of VD, the mode of supplementation also plays a critical role.…”

The Relationships of Serum Vitamin D Concentration with Linear Speed and Change of Direction (COD) Performance in Soccer Players

“…Over the years, numerous studies have been conducted on the effects of vitamin D on the human body [1][2][3]. Previous research has revealed its significant impact on calcium-phosphate metabolism of the body's skeletal system [2,4,5].…”

“…25 hydroxyvitamin D (25(OH)D) is a fat-soluble vitamin that, when converted into its biologicallyactive form, 1,25-dihydroxyvitamin, influences the expression of over 900 genes [6,8,9]. These genes impact a wide variety of health and performance aspects, such as the immune and endocrine systems, exercise-induced inflammation, cardiovascular health, cancer prevention, neurological function, glucose metabolism, as well as bone and muscle structure and metabolism [3,6,8,10,11]. Vitamin D also has a significant impact on mental health, including depression, cognitive disorders, and neurological impairments [1,3,12].…”

“…These genes impact a wide variety of health and performance aspects, such as the immune and endocrine systems, exercise-induced inflammation, cardiovascular health, cancer prevention, neurological function, glucose metabolism, as well as bone and muscle structure and metabolism [3,6,8,10,11]. Vitamin D also has a significant impact on mental health, including depression, cognitive disorders, and neurological impairments [1,3,12]. The crucial impact of vitamin D on muscle cells results from its effects on calcium homeostasis, energy metabolism, phospholipid metabolism, cell proliferation and differentiation, protein synthesis, and mitochondrial function [1,6,13,14].…”