Association of vitamin D status with multiple sclerosis in a case-control study from Morocco

The association between vitamin D deficiency and multiple sclerosis: an updated systematic review and meta-analysis

BACKGROUND

Although there is evidence of a link between vitamin D status and risk of multiple sclerosis (MS), there has been no systematic review where the exposure measure was vitamin D deficiency rather than 25 hydroxy vitamin D (25(OH)D) concentration. We conducted an updated systematic review and meta-analysis to estimate the association between vitamin D deficiency, defined in most studies as a serum 25(OH)D concentration of < 50 nmol L-1, and MS.

METHODS

We searched the MEDLINE, EMBASE, and CINAHL databases to identify relevant publications. We estimated the pooled odds ratio (OR) using a random effects model for the association between vitamin D deficiency and MS, overall and stratified by several factors, including whether or not studies included participants who were taking vitamin D supplements. We also analysed the association between mean 25(OH)D concentration and MS, and used meta-regression to assess the effects of vitamin D supplementation, latitude, age, ethnicity, vitamin D definition and seasonality on the OR estimates. The Newcastle-Ottawa Scale was used to assess study quality.

RESULTS

Results were pooled across 14 case-control studies published between 2007 and 2021 (n = 4130 cases, n = 4604 controls). Persons with vitamin D deficiency had a 54 % higher risk of multiple sclerosis than those with sufficient vitamin D status (OR 1.54; 95 % CI 1.05, 2.24). In studies that excluded participants taking vitamin D supplements (N = 7), the OR was 2.19 (95 % CI: 1.44, 3.35), whereas, in studies that did not exclude participants taking supplements, there was no increase in risk (OR 0.82; 95 % CI: 0.43, 1.58). Mean age (R2 = 27.4 %) and inclusion/exclusion of participants taking supplements (R2 = 33.4 %) contributed most to variability in the OR of vitamin D deficiency and MS.

CONCLUSION

Vitamin D deficiency is associated with an increased likelihood of multiple sclerosis. Maintaining sufficient vitamin D may be an important modifiable risk factor for MS.

Assessment of Vitamin D Status in the Drâa-Tafilalet Population (Morocco) Based on Sociodemographic, Health, and Nutritional Factors

The purpose of this study was to evaluate the vitamin D status and determine the factors influencing it in the Drâa-Tafilalet community (southeastern Morocco). Sociodemographic factors, health, cognitive status, sun exposure, and nutritional conditions were examined to help us understand their association with vitamin D status. Vitamin D data were gathered through laboratory testing, while demographic and health information was collected through interviews with participants in 2023. The study involved 100 participants aged 60 and above, most of whom were women (85%) rather than men (15%). The majority of participants were Arabs (90%), with a minority being Amazigh (10%). The average vitamin D level was 31.83 ± 10.55 ng/mL, varying based on participants' age, education, and gender. Sun-exposed individuals exhibited significantly higher mean vitamin D levels (33.56 ± 11.99 ng/mL) compared to those with limited sun exposure (28.97 ± 9.28 ng/mL). Moreover, the time spent outdoors, seasonal changes, and the duration of sun exposure affected the levels of vitamin D. These findings depict the vitamin D status of the elderly population of Drâa-Tafilalet, recognized as one of Morocco's poorest regions, shedding light on the significant influencers. Nonetheless, additional research is necessary to explore the correlation between dietary habits, sunlight exposure, and vitamin D levels in both young and elderly populations.

Vitamin D deficiency in relation with the systemic and central inflammation during multiple sclerosis

Background

During the last decade, vitamin D (VitD) has become a topic of interest in immune regulation, especially in multiple sclerosis (MS) disease. Amongst the wide range of effects reported for this vitamin on the immune system, a regulatory role on cytokines production has been described. Our aim is to analyze the status of VitD and its correlation with the circulating inflammation and the intrathecal humoral response during MS.

Methods

We analyzed samples of 318 individuals: 108 MS patients and 210 controls. Determination of 25-(OH) VitD3 level in serum was made using electrochemiluminescence method. Circulating inflammatory cytokines (IL-6, IL-8, IL-10, TNF-a, IL12p70 and IL-1b) were investigated using Cytometer Bead Array Technology. The central humoral response was characterized using CSF isofocusing test and IgG Index calculation.

Results

As expected, mean value of VitD was significantly lower in MS group (26 nmol/L) than in control group (34.75 nmol/L) (p=0.002), with a severe deficiency in 67% of MS patients. Mean value of VitD was significantly lower in MS female patients. Regarding cytokines, mean value of TNFa was significantly higher in MS patients with oligoclonal bands of IgG in the CSF. IL6 was positively correlated with IgG level in serum of MS patients.

Conclusions

Our results support the association of VitD deficiency with MS, especially in female patients of our region. However, the vitamin level seems to not correlate with inflammatory cytokines nor with disability. Interestingly, TNFa and IL6 levels were correlated with the intrathecal synthesis of IgG and the circulating IgG level, respectively.

Multifactorial hypovitaminosis D among women in the South-East Oases of Morocco

This study assessed the vitamin D status among women in South-East Oases of Morocco. Two hundred thirty-three healthy volunteer women were recruited at five urban and rural health centers. Hypovitaminosis D is very common in this region and correlated to age, monthly income, skin color, daily sun exposure, BMI, and body fat percentage.

PURPOSE

This study assessed the vitamin D status among women in the Draa-Tafilalet region and its relationship with clinical, anthropometric, and behavioral parameters.

METHODS

The study was carried out with 233 women in consultation at five urban and rural health centers in the South-East region of Morocco. The data collected relate to age, monthly income, educational level, BMI, body fat percentage, daily sun exposure, physical activity level, veil wear, and skin color. The plasma determination of vitamin D was measured by immunofluorescence. Statistical analyses were performed using Python and Jamovi.

RESULTS

The median 25(OH)D plasma concentration was 9.95 ng/mL (IQR: 8-13.18). A total of 50.64% of women had 25(OH)D levels below 10 ng/ml and 47.21% had levels between 10 and 30 ng/mL. Statistical tests showed an association between hydroxyvitamin D plasma levels and age (r =  - 0.139; p = 0.034), monthly income (p = 0.001), BMI (r =  - 0.200; p = 0.002), body fat percentage (r =  - 0.131; p = 0.049), daily sun exposure (r = 0.165; p = 0.012), and skin color (p < 0.001). Binomial logistic regression showed that darker skin was associated with vitamin D deficiency (< 10 ng/mL). It also showed that high income and longer sun exposure could be protecting factors against vitamin D deficiency.

CONCLUSION

The plasma concentrations of vitamin D in women in the Draa-Tafilalet region were low compared to expected results for a high sunshine time area.

Trends in the environmental risks associated with earlier onset in multiple sclerosis

BACKGROUND

Several environmental and lifestyle factors relating to sunlight/vitamin D, body mass index (BMI), and smoking are associated with the risk of developing multiple sclerosis (MS). However, their relation to disease progression, particularly age at symptomatic onset, remains inconsistent, which may be the result of significant changes in human-environment interactions over the last century. This study investigates historical trends in the association between common MS environmental risk factors and age at disease onset.

METHODS

Using a narrative approach, we evaluated the current literature for published studies assessing the association between vitamin-D, BMI, and tobacco smoking exposures with the risk of early/pediatric-onset MS and direct correlations with age at MS onset using MEDLINE, EMBASE, and Web of Science. Measures were plotted by the average calendar year of disease onset for each cohort to examine trends over time. In total, 25, 9, and 11 articles were identified for vitamin D, BMI, and smoking-related exposures, respectively.

RESULTS

Higher sun exposure habits and residential solar radiation were associated with older age at onset. On the contrary, two studies observed a negative correlation between age at onset and serum 25-hydroxyvitamin D (25(OH)D) levels. Higher adolescent BMI was generally associated with younger age at onset, although genetic susceptibility for childhood obesity was not significantly associated. Tobacco smoking was associated with later disease onset, despite being a risk factor for MS. Association with age at onset was inflated for more recent studies relating to smoking, while often weaker for serum vitamin D and BMI.

CONCLUSION

Current findings indicate a likely association between age at onset and environmental risk factors, such as sun exposure, adolescent BMI, and tobacco smoking, in certain populations. However, findings are often inconsistent and assessment of the relationships and potential changes over time require further investigation.

How Does the Immune System Enter the Brain?

Multiple Sclerosis (MS) is considered the most frequent inflammatory demyelinating disease of the central nervous system (CNS). It occurs with a variable prevalence across the world. A rich armamentarium of disease modifying therapies selectively targeting specific actions of the immune system is available for the treatment of MS. Understanding how and where immune cells are primed, how they access the CNS in MS and how immunomodulatory treatments affect neuroinflammation requires a proper knowledge on the mechanisms regulating immune cell trafficking and the special anatomy of the CNS. The brain barriers divide the CNS into different compartments that differ with respect to their accessibility to cells of the innate and adaptive immune system. In steady state, the blood-brain barrier (BBB) limits immune cell trafficking to activated T cells, which can reach the cerebrospinal fluid (CSF) filled compartments to ensure CNS immune surveillance. In MS immune cells breach a second barrier, the glia limitans to reach the CNS parenchyma. Here we will summarize the role of the endothelial, epithelial and glial brain barriers in regulating immune cell entry into the CNS and which immunomodulatory treatments for MS target the brain barriers. Finally, we will explore current knowledge on genetic and environmental factors that may influence immune cell entry into the CNS during neuroinflammation in Africa.

Serum Vitamin D as a Biomarker in Autoimmune, Psychiatric and Neurodegenerative Diseases

Vitamin D is a steroid hormone regulating calcium-phosphorus homeostasis, immune response and brain function. In the past thirty years, an increasing number of cohort studies, meta-analyses and randomized controlled trials (RTCs) evaluated the serum levels of 25-hydroxyvitamin D [25(OH)D], which is considered the Vitamin D status biomarker, in patients affected by neurological, psychiatric and autoimmune diseases. Although an association between low 25(OH)D serum levels and the prevalence of these diseases has been found, it is still unclear whether the serum 25(OH)D measurement can be clinically useful as a biomarker for diagnosis, prognosis and predicting treatment response in neurodegeneration, mental illness and immune-mediated disorders. The lack of standardized data, as well as discrepancies among the studies (in the analytical methods, cut-offs, endpoints and study sets), weakened the findings achieved, hindered pooling data, and, consequently, hampered drawing conclusions. This narrative review summarizes the main findings from the studies performed on serum 25(OH)D in neurological, psychiatric and autoimmune diseases, and clarifies whether or not serum 25(OH)D can be used as a reliable biomarker in these diseases.

Seasonal variability of serum 25-hydroxyvitamin D on multiple sclerosis onset

Vitamin D deficiency is associated with an increased risk of multiple sclerosis (MS). However, its effect on the age of disease onset remains unclear. This study examines the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and age of first symptom onset among recently diagnosed MS patients. Serum 25(OH)D was measured from forty MS patients sampled near disease onset. After correcting seasonal variability, the association between 25(OH)D levels, along with other clinical measures such as IgG index, and age at MS onset was examined using multivariable linear regression. Serum 25(OH)D was not correlated with age at onset (P > 0.5). We observed bias among previously reported associations between 25(OH)D and MS disease measures resulting from non-random distribution of sampling by season. After correcting for seasonal 25(OH)D and other clinical measures, only CSF IgG index remained significantly associated with age at disease onset (β = − 5.35, P = 0.028). In summary, we observed no association between age at onset and serum 25(OH)D levels but observed a negative correlation with CSF IgG index, although this will require further investigation.

Calcium-phosphate homeostasis in secondary progressive multiple sclerosis patients during mitoxantrone therapy

OBJECTIVES

To assess calcium-phosphate parameters in SPMS patients treated with mitoxantrone (MTX).

METHODS

Thirty eight SPMS patients eligible for MTX therapy in the Department of Neurology in Zabrze, Poland were enrolled in a prospective study from March 2016 to November 2019. The parameters of serum calcium-phosphate metabolism and the neurological status according to the Expanded Disability Status Scale (EDSS) were assessed. In patients with hypovitaminosis D, vitamin D (VitD) supplementation was introduced (4000 IU/day for 1 month and later 2000 IU /day).

RESULTS

Most patients were women [57.89%]. The mean age [years] was 56.11 (±7.74). The median time from diagnosis to inclusion day (ID) was 7.50 [4.00-14.00] [years]. Due to VitD supplementation, an increase in serum VitD was observed during the study. 84.21% of patients presented with hypovitaminosis D before MTX treatment compared to 47.37% after treatment. Before MTX therapy, none of the patients underwent surgical repair of the fracture compared to 42.11% of patients after MTX treatment (p < 0.01).

DISCUSSION

Deficiency of VitD was observed at the baseline in most SPMS patients eligible for MTX therapy. Due to adverse reactions to MTX treatment, this therapy requires patient compliance, cautious drug administration and monitoring during the therapy.

Vitamin D and Disease Severity in Multiple Sclerosis-Baseline Data From the Randomized Controlled Trial (EVIDIMS)

Objective: To investigate the associations between hypovitaminosis D and disease activity in a cohort of relapsing remitting multiple sclerosis (RRMS) and clinically isolated syndrome (CIS) patients.

Methods: In 51 RRMS and 2 CIS patients on stable interferon-β-1b (IFN-β-1b) treatment recruited to the EVIDIMS study (Efficacy of Vitamin D Supplementation in Multiple Sclerosis (NCT01440062) baseline serum vitamin D levels were evaluated. Patients were dichotomized based on the definition of vitamin D deficiency which is reflected by a < 30 vs. ≥ 30 ng/ml level of 25-hydroxyvitamin D (25(OH)D). Possible associations between vitamin D deficiency and both clinical and MRI features of the disease were analyzed.

Results: Median (25, 75% quartiles, Q) 25(OH)D level was 18 ng/ml (12, 24). Forty eight out of 53 (91%) patients had 25(OH)D levels < 30 ng/ml (p < 0.001). Patients with 25(OH)D ≥ 30 ng/ml had lower median (25, 75% Q) T2-weighted lesion counts [25 (24, 33)] compared to patients with 25(OH)D < 30 ng/ml [60 (36, 84), p = 0.03; adjusted for age, gender and disease duration: p < 0.001]. Expanded disability status scale (EDSS) score was negatively associated with serum 25(OH)D levels in a multiple linear regression, including age, sex, and disease duration (adjusted: p < 0.001).

Interpretation: Most patients recruited in the EVIDIMS study were vitamin D deficient. Higher 25(OH)D levels were associated with reduced T2 weighted lesion count and lower EDSS scores.