Risk factors for vitamin D deficiency in women aged 20–50 years consulting in general practice: a cross-sectional study

Interaction of Passive Smoking and Diet Habits on Vitamin D Deficiency among Women of Reproductive Age in Rural Central China

Objective: Maternal dietary undernutrition is known to be associated with the risk of vitamin D (VD) deficiency. However, whether the risk of VD deficiency in women of reproductive age is influenced by the interaction between passive smoking and inadequate nutrition remains unknown. The aim of this study is to explore the interaction between passive smoking and dietary undernutrition on the risk of VD deficiency. Methods: A population-based case−control study including 1151 non-pregnant women of reproductive age between 18 and 40 years old was conducted in Henan Province, China from 2009 to 2010. Blood samples and information on exposure factors were collected. The prevalence of VD deficiency was estimated based on a result of serum 25-hydroxyvitamin D [25(OH)D] < 26.0 ng/mL. A multivariate logistic regression analysis was performed to explore the risk of VD deficiency. Results: The prevalence of VD deficiency was 61.5%. After adjusting for potential confounding factors, the interactions between passive smoking and no nutritional supplementation, passive smoking and insufficient egg intake, and passive smoking and insufficient milk dairy products intake were associated with the risk of VD deficiency, and the adjusted ORs were 3.40 (95% CI 2.26−5.13), 2.87 (95% CI 2.20−4.10), and 2.18 (95% CI 1.33−3.58), respectively. The interaction coefficients were calculated to be 2.35, 2.79, and 1.70, respectively, indicating there were significant interaction effects, as all of the coefficients were higher than 1. Conclusions: Our findings present that the risk of VD deficiency was potentially influenced by interactions between passive smoking and inadequate nutrition. Passive smoking might strengthen the effect of inadequate nutrition on the risk of VD deficiency among rural women of reproductive age. More attention should be paid to the health education and nutritional status improvement of women of reproductive age, especially in rural areas of developing countries.

Micronutrient deficiencies and anaemia associated with body mass index in Australian adults: a cross-sectional study

AIM

To estimate the prevalence of micronutrient deficiencies and anaemia, and their association with body mass index (BMI) categories among Australian adults.

METHOD

We analysed data from the 2011-2013 Australian Health Survey from 3539 participants aged 18 years and over (without known pregnancy) with measured weight and height, and nutrient biomarkers. To address complex sampling, survey weights were used when estimating the prevalence of micronutrient deficiencies (vitamin B₁₂ deficiency; serum vitamin B₁₂<145 pmol/L; iron deficiency; ferritin<30 µg/L and vitamin D deficiency; 25-hydroxyvitamin D<50 nmol/L) and anaemia (haemoglobin <120 g/L for females and <130 g/L for males) and when assessing associations with logistic regression models with adjusted ORs (AORs) for BMI categories: healthy weight (BMI 18.5 to <25.0 kg/m²), reference; overweight (BMI 25.0 to <30.0 kg/m²), obesity class I (BMI 30.0 to <35.0 kg/m²), obesity class II/III (BMI 35.0 kg/m² or more).

RESULT

The prevalence of vitamin B₁₂ deficiency (range 0.9%─2.8%) and anaemia (range 3.9%─6.7%) were variable across BMI groups. The prevalence of iron deficiency in the obesity class I group was 12.0 percentage points lower than healthy weight group with an AOR of 0.50 (95% CI 0.30 to 0.83). The prevalence of vitamin D deficiency in the obesity class II/III group was 7.9 percentage points higher than the healthy weight group with an AOR of 1.62 (95% CI 1.01 to 2.60). Vitamin B₁₂ deficiency and anaemia were not consistently associated with BMI groups.

CONCLUSION

We found a consistent association between severe obesity and vitamin D deficiency in Australian adults. We also found obesity class I was negatively associated with iron deficiency, whereas there was no consistent association between BMI groups and vitamin B₁₂ deficiency and anaemia. Public health strategies are needed to prevent vitamin D deficiency in this high-risk population.

Religious dietary rules and their potential nutritional and health consequences

BACKGROUND

The vast majority of the world population declares affiliation to a religion, predominantly Christianity and Islam. Many religions have special dietary rules, which may be more or less strictly adhered to.

METHODS

Religious food rules were collected from holy books and religious websites as well as their translation into dietary practices. The literature was searched for potential associations between these rules and potential nutritional consequences.

RESULTS

Jewish, Islamic and Indian religions support prolonged breastfeeding. Religious avoidance of alcohol is probably beneficial to health. When strictly applied, a few rules may lead to nutritional inadequacies, mainly in populations living in unfavourable socio-economic or environmental conditions. In Jewish and Muslim observants, animal slaughtering procedures may increase the risk of iron deficiency. Jews may be at risk of excess sodium intake related to home-prepared foods. A vegan diet, as observed by some believers, often by drifting from original precepts, or by some Hindus or Buddhists, may result in vitamin B12, calcium, iron, zinc, selenium and n-3 fatty acids deficiencies.

CONCLUSION

When implemented in accordance with the rules, most religious food precepts are not detrimental to health, as suggested by the fact that they have more or less been followed for millennia. Nevertheless, some practices may lead to nutritional inadequacies, such as iron, calcium, vitamin D and vitamin B12 deficiencies. Patients with low socio-economic status, children and women of childbearing age are of particular risk of such deficiencies. Being aware of them should help health professionals to take an individualized approach to decide whether to supplement or not.

[Vitamin D Deficiency in Sports]

Vitamin D Deficiency in Sports Abstract. A deficiency in vitamin D is very common in the general population as well as in athletes. The aim of this overview is to assess the level of knowledge about the importance of vitamin D for athletes. A deficiency in vitamin D is present in up to 90 % of athletes. Risk groups are young athletes, female athletes, athletes with a limitation such as paraplegia, vegetarians, athletes with a resorption disorder such as celiac disease, athletes training and competing indoors (e.g. ice hockey, basketball, boxing, rhythmic gymnastics), and older athletes. Dark skin pigmentation, the use of sunscreen, the time of day of the training (early morning, late evening) and the geographical location influence the risk for a deficiency in vitamin D. Exposure to the sun and a balanced diet are often not enough to prevent a vitamin D deficiency.

Poor dietary consumption and limited sun exposure are risk factors for vitamin D deficiency in premenopausal Kuwaiti women: A cross-sectional study

Background: Low serum vitamin D levels are reported constantly among females living in the Arabian Gulf countries, presumably due to their lifestyle, which limits direct sun exposure. Because Vitamin D deficiency has been implicated in a wide range of ailments, healthy females with the deficiency might be at risk for developing many health problems. Thus, the aim was to assess lifestyle risk factors for vitamin D deficiency in healthy women in Kuwait. Methods: A total of 104, disease-free, premenopausal women were recruited for assessment of their serum 25OHD and intact PTH levels. Physical examination, blood withdrawal and interviewer-administered questionnaires were used to collect the relevant data. Associations were detected statistically using nonparametric tests and logistic regression was used to identify risk factors for vitamin D deficiency. Results: Vitamin D deficiency ( < 25 nmol/L) occurred in 84.6%, and hyperparathyroidism ( ≥ 6.9 pmol/L) occurred in 25% of women, among which all were vitamin D deficient. Significant risk factors of vitamin D deficiency were nondaily milk intake (OR:25, CI%:4.2-147), no fish intake (OR:5, CI%:1-22.8), and no weekend sun exposure (OR:8.2, CI%:1.28-52.6). Having PTH ≥ 6 pmol/L was also associated with a higher likelihood of having vitamin D deficiency. Conclusion: Vitamin D deficiency is very common in disease-free, premenopausal Kuwaiti women and can be avoided by improving food consumption and obtaining more sun exposure.

Association between serum vitamin D status and health-related quality of life (HRQOL) in an older Korean population with radiographic knee osteoarthritis: data from the Korean national health and nutrition examination survey (2010-2011)

Background

Vitamin D is important in bone health and its relationship with osteoarthritis has recently been reported. Both vitamin D deficiency and knee osteoarthritis are age dependent and are known to affect quality of life (QOL) in older populations. In this study, we aimed to determine the association between vitamin D status and health-related quality of life (HRQOL) in an older Korean population with knee osteoarthritis.

Methods

A total of 2,165 participants aged ≥50 years with radiographic knee osteoarthritis defined as Kellgren-Lawrence (KL) grade ≥2 were selected from data from the 5th Korean National Health and Nutrition Examination Survey (KNHANES V), a representative cross-sectional nationwide survey conducted in 2010–2011. They stratified into two levels by vitamin D status (deficiency <10 ng/dL and normal ≥10 ng/dL). HRQOL was measured using the EuroQOL visual analogue scale (EQ-VAS) and the five dimensions and summary index of the EuroQOL-5 dimension (EQ-5D).

Results

The vitamin D deficiency group was more likely to report problems with mobility, self-care, and usual activities. Vitamin D deficiency was significantly associated with poor HRQOL indicated by the lowest quartile of EQ-VAS (unadjusted odds ratio [OR] =1.832, p = 0.006) and the lowest quartile of the EQ-5D index (unadjusted OR = 1.992, p = 0.003). Theses associations of vitamin D status with EQ-VAS and EQ-5D index were maintained after adjustment for age and sex (Model 1: OR = 1.677, p = 0.022 and OR = 1.701, p = 0.021, respectively). The significant associations of vitamin D status with EQ-VAS were maintained after adjustment for other possible covariates (Model 3: OR = 1.562, p = 0.044). Also, a trend of associations between vitamin D status and EQ-5D index were shown after adjustment for other covariates (Model3: OR = 1.681, p = 0.056).

Conclusion

This is the first study to reveal that vitamin D status is independently associated with HRQOL in an older Korean population with knee osteoarthritis. Our results suggest that the maintenance of sufficient vitamin D status may be important to prevent QOL decline in older populations with knee osteoarthritis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12955-015-0245-1) contains supplementary material, which is available to authorized users.

Impact of vitamin D supplementation on health-care use in a 25-hydroxyvitamin D-tested population in France: a population-based descriptive cohort study

OBJECTIVE

Chronic vitamin D deficiency has been associated in some patients with diffuse musculoskeletal pain. These unspecific symptoms may partly explain why vitamin D deficiency is often diagnosed late. Our aim was to analyse health-care claims after vitamin D supplementation in patients likely to have vitamin D deficiency.

DESIGN

Ambulatory health-care claims were compared before and after a vitamin D supplementation prescribed following a 25-hydroxyvitamin D assay.

SETTING

Health Insurance Fund (FHIF) database of the Rhône-Alpes area, France.

SUBJECTS

Among patients reimbursed for a 25-hydroxyvitamin D assay between 1 December 2008 and 31 January 2009, those supplemented with vitamin D after the assay were matched on the date of assay to patients who did not receive vitamin D.

RESULTS

Among the 3023 patients who had a 25-hydroxyvitamin D assay, 935 were consequently supplemented and matched to 935 patients not supplemented. Their median age was 50·0 and 49·5 years, respectively. Patients supplemented decreased their muscle relaxant consumption whereas no change was observed in the reference group, the difference between the two groups was significant (P=0·03). Second and third Pain Relief Ladder prescriptions decreased in both groups but not significantly differently between groups (P=0·58). There was a decrease in prescriptions of biological examination in both groups with no significant difference.

CONCLUSIONS

Besides a decrease in muscle relaxant prescriptions in the supplemented group, it was difficult to assess the impact of vitamin D supplementation in patients likely to have vitamin D deficiency. Prospective cohort studies and randomized trials are needed to assess the efficiency of screening and supplementing vitamin D deficiency.

Physical performance and 25-hydroxyvitamin D: a cross-sectional study of pregnant Swedish and Somali immigrant women and new mothers

BACKGROUND

Severe vitamin D deficiency can impair muscle strength. The study aims were to examine physical performance in the hands and upper legs, and analyze plasma 25-hydroxyvitamin D (25(OH)D) concentrations in women with presumably low (veiled, Somali-born) and high levels (unveiled, Swedish-born).

METHODS

Women (n=123, 58% Swedish) enrolled at a Swedish antenatal clinic, latitude 60° N, were recruited. Plasma 25(OH) D was analyzed, measured as nmol/L, then categorized as <10 = undetectable, 10-24, 25-49, 50-74 or >75. Muscle strength was tested: maximal hand grip strength (in Newtons, N), and upper leg performance (categorized as able/unable to perform squatting, standing on one leg, standing from a chair, and lifting their hips). Social and anthropometric data were collected. Non-parametric statistics tested the data for differences in their ability to perform the tests across 25(OH)D categories. Undetectable values (<10 nmol/L) were replaced with '9' in the linear correlation statistics. A final main effect model for grip strength (in N) was calculated using stepwise linear regression for independent variables: country of birth, 25(OH)D levels, age, height, weight, physical activity, lactation status, parity, and gestational age.

RESULTS

Somali participants (35%) had 25(OH)D levels of <10 nmol/L, and 90% had <25 nmol/L; 10% of Swedish participants had <25 nmol/L of 25(OH)D, and 54% had <50 nmol/L. Somali women had a relatively weak grip strength compared with Swedish women: median 202 N (inter-quartile range 167-246) vs. median 316 N (inter-quartile range 278-359), respectively. Somali women were also weak in upper leg performance: 73% were unable to squat, 29% unable to stand on one leg, and 21% could not lift their hips (not significant across 25(OH)D categories); most Swedish women could perform these tests. In the final model, grip strength (N) was significantly associated with 25(OH)D levels (B 0.94, p=0.013) together with Somali birth (B -63.9, p<0.001), age (B 2.5, p=0.02) and height (B 2.6, p=0.01).

CONCLUSIONS

Many Somali women had undetectable/severely low 25(OH)D concentrations and pronounced hand and upper leg weakness; grip strength was strongly associated with 25(OH)D. Maternity health care personnel should be aware of this increased frequency and manage care accordingly.

Influence of diet and sample collection time on 77 laboratory tests on healthy adults

OBJECTIVES

We studied the effect of a standardized breakfast or lunch before blood sampling on 77 analytes.

DESIGN AND METHODS

The mean difference between assays from 20 healthy adults was calculated on blood samples taken before and after food intake. Significant differences were tested using two-tailed Student t-test and compared to the acceptable limits derived from analytical and intraindividual biological variation.

RESULTS

Most of the analytes investigated were not significantly affected by food intake. Six of them were influenced by breakfast or lunch: triglycerides, glucose, creatinine, C-peptide and insulin were significantly upregulated, whereas testosterone was downregulated. Fourteen parameters were more influenced by time of sampling than by meals: nine decreased during the day (total bilirubin, BNP, myoglobin, cortisol, TSH, C-telopeptide, prolactin, ACTH, uric acid) and two increased (white blood cells, neutrophils). Three parameters showed levels that were similar at 9:00 am and 5:00 pm but their lowest level at 12:30 pm (inorganic phosphorus, osteocalcin, PTH).

CONCLUSIONS

Fasting is necessary for some laboratory tests. Clinicians should be aware of variations due to sampling time before ordering non-fasting tests, and in the subsequent interpretation of results.

Vitamin D supplementation for diffuse musculoskeletal pain: results of a before-and-after study

BACKGROUND

Several studies have shown that vitamin D supplementation could be useful for treating diffuse musculoskeletal (DMS) pain in adults.

OBJECTIVES

The aim of this study was to evaluate the effects of correcting a vitamin D deficiency (≤ 50 nmol/l) on DMS pain and quality of life in adults.

METHODS

A pragmatic prospective study was conducted in a general practice setting in the Rhone-Alps area between 1 February and 30 April 2009. Patients between the ages of 18 and 50 years old who consulted their general practitioner (GP) for DMS pain or chronic unexplained asthenia and had a deficient serum 25 (OH) D level with no signs of any other disease were enrolled in this study. The patients received high doses of vitamin D supplements (400 000 to 600 000 units). Mean pain evaluation scores were evaluated before and after vitamin D supplementation using mixed models and accounting for repeated measures.

RESULTS

Before vitamin D supplementation, the adult study cohort (n = 49) had an adjusted mean serum 25 (OH) D level of 23.7 nmol/l, a mean pain evaluation score of 5.07 and a mean quality of life score of 3.55. After vitamin D supplementation, the adjusted mean serum 25 (OH) D level increased to 118.8 nmol/l (P < 0.001), the mean quality of life score increased to 2.8 nmol/l (P < 0.001) and the mean pain evaluation score decreased to 2.8 (P < 0.001).

CONCLUSION

In this small before-and-after study, vitamin D supplementation decreased pain scores in adult patients with diffuse musculoskeletal pain and vitamin D deficiency. These results must be confirmed by further studies.

The predictive factors of low serum 25-hydroxyvitamin D and vitamin D deficiency in patients with systemic lupus erythematosus

Vitamin D is a steroid hormone with pleiotropic effects. The association between serum 25-hydroxyvitamin D level [25(OH) D] and lupus nephritis are not clearly known. We aim to determine serum 25(OH) D levels in patients with inactive SLE, active SLE without lupus nephritis (LN) and active SLE with LN and to identify clinical predictor of vitamin D deficiency. One hundred and eight SLE patients were included. Patients were classified as Group (Gr) 1, 2 and 3 if they had SLE disease activity index (SLEDAI) <3, ≥ 3 but no LN and ≥ 3 with LN. Important baseline characteristics were collected. 25(OH) D was measured by high performance liquid chromatography (HPLC). SLEDAI in Gr1, Gr2 and Gr3 was 0.7 (0.9), 5.6 (2.3) and 9.2 (5.2), respectively. 43.5 % had vitamin D insufficiency and 29.6 % had vitamin D deficiency. Mean 25(OH) D in each groups was 28.3 (8.0), 26.7 (9.5) and 19.9 (7.6) ng/ml (p < 0.001 comparing Gr1 and 3) (p = 0.003 comparing Gr2 and 3). Vitamin D deficiency was found in 11.1, 22.2 and 55.6 % of Gr1, 2 and 3. Linear regression analysis found that 25(OH) D was significantly correlated with serum albumin (r = 0.28, p = 0.004), inversely correlated with SLEDAI (r = -0.22, p = 0.03) and urinary protein creatinine index (UPCI) (r = -0.28, p = 0.005), but not with sun exposure score, body mass index and estimated GFR. Only UPCI was significantly inversely correlated with 25(OH) D (p = 0.02) from multiple linear regression. LN was a significant predictor of vitamin D deficiency from multivariate logistic regression (OR 5.97; p = 0.006). Vitamin D deficiency and insufficiency was found in 93 and 86 % of LN with proteinuria ≥ and <500 mg/day. We conclude that SLE patients with LN have significantly lower vitamin D level than inactive SLE and active SLE without LN. Hence, nephritis is a significant predictor of vitamin D deficiency in SLE patients.

A retrospective cohort study on the influence of UV index and race/ethnicity on risk of stress and lower limb fractures

Background

Low vitamin D status increases the risk of stress fractures. As ultraviolet (UV) light is required for vitamin D synthesis, low UV light availability is thought to increase the risk of vitamin D insufficiency and poor bone health. The purpose of this investigation was to determine if individuals with low UV intensity at their home of record (HOR) or those with darker complexions are at increased risk of developing stress fractures and lower limb fractures during U.S. Army Basic Combat Training (BCT).

Methods

This was a retrospective cohort study using the Armed Forces Health Surveillance Center data repository. All Basic trainees were identified from January 1997 to January 2007. Cases were recruits diagnosed with stress fractures and lower limb fractures during BCT. The recruit’s home of record (HOR) was identified from the Defense Manpower Data Center database. The average annual UV intensity at the recruits’ HOR was determined using a U.S National Weather Service database and recruits were stratified into low (≤3.9); moderate (4.0-5.4), and high (≥5.5) UV index regions. Race was determined from self-reports.

Results

The dataset had 421,461 men and 90,141women. Compared to men, women had greater risk of developing stress fractures (odds ratio (OR) = 4.5, 95% confidence interval (95%CI) = 4.4-4.7, p < 0.01). Contrary to the hypothesized effect, male and female recruits from low UV index areas had a slightly lower risk of stress fractures (male OR (low UV/high UV) = 0.92, 95%CI = 0.87-0.97; females OR = 0.89, 95%CI = 0.84-0.95, p < 0.01) and were at similar risk for lower limb fractures (male OR = 0.98, 95%CI = 0.89-1.07; female OR = 0.93, 95%CI = 0.80-1.09) than recruits from high UV index areas. Blacks had lower risk of stress and lower limb fractures than non-blacks, and there was no indication that Blacks from low UV areas were at increased risk for bone injuries.

Conclusions

The UV index at home of record is not associated with stress or lower limb fractures in BCT. These data suggest that UV intensity is not a risk factor for poor bone health in younger American adults.

[Musculoskeletal chronic pains and Vitamin D deficiency. Study before after in general practice]

OBJECTIVES

The objective of this study was to evaluate the effect of the correction of vitamin D deficiency (defined by a rate≤50 nmol/l) on the pain, fatigue and quality of life.

METHODS

A pragmatic prospective study was conducted in Rhone-Alpes area, in general practices between February 1 and April 30, 2009. All patients aged 18 to 50 years consulting for diffuse musculoskeletal pain and/or chronic unexplained fatigue, with the only abnormality deficient serum vitamin D were enrolled in this study. They might agree to complete questionnaires on quality of life, pain assessment and control their vitamin D levels after treatment.

RESULTS

Forty-nine complete records were analyzed. The deficiency was severe (mean 26 nmol/l). High doses of vitamin were necessary to correct deficiency, between 400,000 to 600,000 units. The correction of vitamin D deficiency resulted in a significant decrease in the level of pain intensity according to verbal rating scale (P=0.034) and the Digital Scale (P<0.001), consumption of analgesics (P=0.002) and discomfort in carrying out activities of daily living following: the shopping, cleaning, walking for more than a kilometer (P<0.001) and dressing (P=0.012).

CONCLUSION

The correction has had a positive impact both physical, mental and social activities. Non-specific musculoskeletal pain or unexplained asthenia are common in primary care. Make a dosage of vitamin D and correct deficits is a necessity before performing complex and expensive examinations.

Vitamin d deficiency in patients with systemic lupus erythematosus

OBJECTIVES

Hypovitaminosis D is common in the general population. Many studies that have been conducted to show the association between vitamin D deficiency and systemic lupus erythematosus (SLE) reveal that deficiencies in vitamin D are common in this group of patients. Our aim was to study the relationship between 25(OH)D and disease activity in patients with SLE.

METHODS

Retrospective cohort study of patients with SLE who were followed up at King Abdulaziz University Hospital, Jeddah, from January 2007 to November 2010. Demographic and clinical data were recorded and the 25(OH)D levels of the patients were measured. Chi square tests, Student's t-test, ANOVA and Pearson tests were used for data analysis. ANOVA test was followed by Bonferroni correction. A p-value <0.05 was considered significant.

RESULTS

Ninety-five patients with SLE were enrolled in the study. The levels of 25(OH)D were significantly lower in patients with active SLE (n=41; 43%) than in those with inactive disease (n=54; 57%; p=0.04). The mean (SD) levels were 22.3 (14) nmol/L for patients with active disease against 25.0 (14) nmol/L for patients with inactive SLE. No correlation was detected between 25(OH) D levels and disease activity score evaluated by SLEDAI-2K. By Pearson correlation, a significant negative correlation existed between 25(OH) D and anti ds-DNA (r=-0.38; p<0.001); a positive correlation existed between 25(OH)D levels and C4 (r=0.25; p=0.25). By chi square testing, azathioprine treatment (OR=3.5), low C4 (OR= 2.23), low C3 (OR=1.92), and active disease (OR=1.6) were associated with 25(OH)D deficiency in SLE patients.

CONCLUSION

Vitamin D deficiency is frequent in patients with SLE. Patients with SLE have a higher risk of developing 25(OH)D deficiency in the presence of low serum C3 and C4 levels, and high anti-dsDNA levels.

Vitamin D and musculoskeletal status in Nova Scotian women who wear concealing clothing

Bone and muscle weakness due to vitamin D deficiency is common among Muslim women who reside in sunny, equatorial countries. The purpose of this study was to determine if living in a northern maritime location additionally disadvantages women who wear concealing clothes. A cross-sectional matched pair design was used to compare women who habitually wore concealing clothing with women who dressed according to western norms. Each premenopausal hijab-wearing woman (n = 11) was matched by age, height, weight and skin tone with a western-dressed woman. Subjects were tested by hand grip dynamometry to assess muscular strength and by quantitative ultrasound at the calcaneus to assess bone status. Nutritional intake was obtained by 24 h recall. Serum 25-hydroxyvitamin D (s-25(OH)D) status was determined in seven matched pairs. The hijab group had lower s-25(OH)D than women who wore western clothes (40 ± 28 vs. 81 ± 32 nmol/L, p= 0.01). Grip strength in the right hand was lower in the hijab-wearing women (p = 0.05) but this appeared to be due to less participation in intense exercise. Bone status did not differ between groups (p= 0.9). Dietary intake of vitamin D was lower in the hijab-wearers (316 ± 353 vs. 601 ± 341 IU/day, p= 0.001). This pilot study suggests that women living in a northern maritime location appear to be at risk for vitamin D insufficiency and therefore should consider taking vitamin D supplements.

Vitamin D deficiency as marker for disease activity and damage in systemic lupus erythematosus: a comparison with anti-dsDNA and anti-C1q

Objectives: To study the sensitivity and specificity of vitamin D deficiency for predicting disease activity and damage of systemic lupus erythematosus (SLE) in comparison with anti-dsDNA and anti-C1q. Methods: Consecutive patients who fulfilled four or more ACR criteria for SLE were studied. Levels of 25-hydroxyvitamin D3, anti-C1q, anti-dsDNA and complement levels were measured. Relationship among these markers, concurrent disease activity and damage scores of SLE was studied by Spearman's rank correlation method. Results: In total, 290 SLE patients were studied (95% women; mean age 38.9 ± 13.1 years; SLE duration 7.7 ± 6.7 years). Clinical or serological lupus activity (SLEDAI ≥ 1) was present in 225 (78%) patients. Vitamin D deficiency (< 15 ng/ml) was detected in 78 (27%) patients. Levels of 25-hydroxyvitamin D3 correlated inversely with the clinical SLE disease activity score (Rho = −0.26; p < 0.001). A negative correlation was also observed between 25-hydroxyvitamin D3 and anti-dsDNA levels (Rho = −0.13; p = 0.02), or anti-C1q (Rho = −0.14; p = 0.02). However, there was no significant relationship between levels of 25-hydroxyvitamin D3 and complement C3 (Rho = 0.09; p = 0.12) or C4 (Rho = 0.09; p = 0.13). Both 25-hydroxyvitamin D3 deficiency and anti-C1q were more specific but less sensitive than anti-dsDNA for concurrent clinical renal and non-renal SLE activity. Levels of 25-hydroxyvitamin D3, anti-dsDNA or anti-C1q did not correlate significantly with the SLE damage scores. Conclusions: 25-hydroxyvitamin D3 correlated inversely and significantly with clinical SLE activity, anti-C1q and anti-dsDNA titers, but not with complement levels or damage scores. Deficiency of 25-hydroxyvitamin D3 was as specific as anti-C1q, but less sensitive than anti-dsDNA, for detecting concurrent renal and non-renal clinical activity of SLE.