A Single Vitamin D3 Bolus Supplementation Improves Vitamin D Status and Reduces Proinflammatory Cytokines in Healthy Females.

Vitamin D deficiency is a global health problem that not only leads to metabolic bone disease but also to many other illnesses, most of which are associated with chronic inflammation. Thus, our aim was to investigate the safety and effectiveness of a single high dose of vitamin D3 (80,000 IU) on vitamin D status and proinflammatory cytokines such as interleukin (IL)6, IL8 and tumor necrosis factor (TNF) in healthy Saudi females. Fifty healthy females were recruited and orally supplemented with a single vitamin D3 bolus (80,000 IU). All participants donated fasting blood samples at baseline, one day and thirty days after supplementation. Serum 25-hydroxyvitamin D3 (25(OH)D3), IL6, IL8, TNF, calcium, phosphate, parathyroid hormone (PTH) and blood lipid levels were determined. Serum 25(OH)D3 significantly increased one and thirty days after supplementation when compared with baseline without causing elevation in calcium or phosphate or a decrease in PTH to abnormal levels. In contrast, the concentrations of the three representative proinflammatory cytokines decreased gradually until the end of the study period. In conclusion, a single high dose (80,000 IU) is effective in improving serum vitamin D status and reducing the concentration of the proinflammatory cytokines in a rapid and safe way in healthy females.

A Single Oral Vitamin D3 Bolus Reduces Inflammatory Markers in Healthy Saudi Males.

Vitamin D deficiency has increased in the general population and is a public health issue. Vitamin D plays an important role in regulating the immune system, e.g., by modulating the production of inflammatory cytokines. In most countries, the recommended maximal daily dose of vitamin D3 is 4000 IU (100 µg) per day. In this study, we investigated whether a single vitamin D3 bolus can reduce the levels of the inflammatory markers interleukin (IL) 6, IL8 and tumor necrosis factor (TNF) within one month. Fifty healthy Saudi males were recruited from the local community in Jeddah city and were orally supplemented with a single dose of 80,000 IU vitamin D3. Serum samples were collected at time points 0, 1 and 30 days, and serum levels of IL6, IL8 and TNF, parathyroid hormone (PTH), 25-hydroxyvitamin D3 (25(OH)D3), triglycerides, cholesterol, calcium (Ca2+) and phosphate (PO4-) were determined. On average, the vitamin D3 bolus resulted in a significant increase in vitamin D status as well as in a significant decrease in the levels of inflammatory cytokines even one month after supplementation without changing serum Ca2+, PO4- or lipid levels. In conclusion, single high-dose vitamin D3 supplementation is safe for reducing inflammation markers and may lead to an update of current recommendations for vitamin D intake, in order to prevent critical health problems.

Associations of Vitamin D Levels and Vitamin D Receptor Genotypes with Patient-Reported Outcome/Disease Activity in Patients with Rheumatoid Arthritis.

BACKGROUND: The aim of this study is to evaluate the prevalence of vitamin-D insufficiency and vitamin-D receptor (VDR) polymorphisms in rheumatoid arthritis (RA) patients and its association with disease activity and patient reported outcomes (PROs). METHODS: Eighty-two individuals were included in a cross-sectional study (41 RA patients, 41 controls). Prior to assessment, each patient completed a PRO questionnaire. Serum vitamin-D levels and genotyping for VDR were assessed. Vitamin-D deficient patients received vitamin-D supplementation. Re-assessment of disease activity (DAS28) was performed after 9-months. RESULTS: Low vitamin-D levels were more frequent in RA patients (p < 0.01). A negative, but insignificant, association with DAS-28 score was identified; whereas, there was a significant negative association with the PROs (p < 0.01). Vitamin-D supplementation was associated with significant improvement in the patients' scores for pain, fatigue, global assessment, physical disability, and quality of life. In contrast to the control group, the frequency of the recessive TaqI and FokI genotypes was higher in RA patients. CONCLUSIONS: In RA patients, serum vitamin-D level was significantly and inversely associated with both PROs and disease activity. The TaqI and FokI fragment length polymorphisms of VDR significantly contributed to the risk of RA. Having a significant positive impact on patient reported outcomes, vitamin-D supplementation may have a role in RA management.

Association of Paraoxonase 1 Polymorphism and Serum 25-Hydroxyvitamin D with the Risk of Cardiovascular Disease in Patients with Rheumatoid Arthritis.

BACKGROUND: Patients with rheumatoid arthritis (RA) have significantly increased cardiovascular (CV) morbidity and mortality that are not accounted for by traditional risk factors alone. Paraoxonase 1 (PON1) and 25-hydroxyvitamin D have been shown to be involved in the pathogenesis of CV diseases. Objective: This study aimed to investigate PON1 gene polymorphism and serum 25-hydroxyvitamin D concentrations in RA patients, and to determine their association with CV risk in RA. METHODS: Serum samples from 46 RA patients and 45 healthy controls were tested for PON1 R192Q genotypes and serum vitamin D concentrations. The cardiovascular risks were assessed by Q-risk. Lipoprotein cholesterol levels, traditional CV risk factors, medication use, and RA disease activity status were also assessed. RESULTS: PON1 polymorphism and low serum 25-hydroxyvitamin D were significantly associated with increased CV risk (p < 0.05). Compared to patients with either the PON1 QQ genotype or the QR genotype, patients with the RR genotype demonstrated decreased CV risk on multivariate analysis, controlling for traditional CV risk factors, C-reactive protein levels, prednisone use, and cholesterol-lowering medication use (p < 0.05). CONCLUSIONS: There was a relationship of the genetic determinants of paraoxonase 1 (PON1 192) and serum 25-hydroxyvitamin D to CV risk in RA patients. Paired measurement of paraoxonase 1 genotype and serum 25-hydroxyvitamin D can be used as biomarkers of CV risk in RA patients.