Vitamin D status, dependence on age, and seasonal variations in the concentration of vitamin D in Croatian postmenopausal women initially screened for osteoporosis

Vitamin D Status and Associated Factors of Older Adults in the Cross-Sectional 2015-2017 Survey

Vitamin D is beneficial for maintaining good health; however, there is a lack of nationally representative data reported, particularly in older adults. To better understand the nutritional status of vitamin D and its influencing factors on Chinese older adults, we adopted stratified random sampling to select serum samples originating from the Chronic Disease and Nutritional Survey Biobank of Chinese Residents in 2015-2017. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by enzyme-linked immunoassay. The OR and PR of associated factors for vitamin D deficiency and insufficiency were calculated. In the study, a total of 6273 participants were included. Median serum 25(OH)D concentration was 18.48 (13.27-24.71) ng/mL. The overall rate of vitamin D deficiency and insufficiency was 58.27% (<20 ng/mL), and the VDD rate was 22.17%, which is worse than 5 years ago by nearly 20%. The likelihood of vitamin D deficiency and insufficiency is increased in women, people aged and above 70 years, ethnic minorities, people living in urban areas, midlands, or western areas, warm or medium temperate zones, with middle school and above education level, and people with abdominal obesity and anemia would increase the possibility of vitamin D deficiency and insufficiency with latitude having the greatest impact on vitamin D deficiency and insufficiency. Overall, vitamin D deficiency and insufficiency are very common in Chinese older adults. They should be encouraged to improve their vitamin D nutritional status through enough sunshine exposure and increasing vitamin D intake through diet or supplements.

Prevalence of Vitamin D Deficiency and Insufficiency in Kosovo Population

BACKGROUND: Vitamin D deficiency is a global health problem, but it is not known about its status in the Kosovo population. AIM: The purpose of this study is to determine the status of Vitamin D deficiency and insufficiency in our population. MATERIALS AND METHODS: Data collection was done from January 2020 to July 2021, during which period blood samples were collected. The sampling was done for 769 selected subjects and statistical data (frequency, mean values, and standard deviation) have been analyzed for 25-hydroxyvitamin D [25(OH)D] concentration. They were categorized by age group, gender, and level of 25(OH)D. The prevalence and percentage of Vitamin D deficiency and insufficiency in the study population were evaluated. RESULTS: The mean concentration of 25(OH)D in the serum of the study group was 18.3 ng/ml. The mean value was significantly lower for females when compared for that of males (17.89 and 19.58 ng/ml, respectively), with p < 0.0035, but there was no significant difference between age groups. The level of 25(OH)D less than 20 ng/ml was observed in 62% of the cases in our study population with a slight difference between female (63.6%) and male (57.2%) group. The age group of >60 had 25(OH)D deficiency in 62.3% of cases when compared to other age group categories. Vitamin D deficiency was present in 20.2% of cases; meanwhile, its insufficiency was present in 41.9% of cases. Vitamin D deficiency was observed in 21.1% of females and 17.1% of males, while 42.4% of females, respectively, and 40.1% of males had Vitamin D insufficiency. CONCLUSION: The mean values of 25(OH)D in the study population are relatively low, which corresponds to significant Vitamin D deficiency and insufficiency in all age groups, and which may also have serious implications for their overall health.

'Scientific Strabismus' or two related pandemics: coronavirus disease and vitamin D deficiency

The WHO has announced the novel coronavirus disease (COVID-19) outbreak to be a global pandemic. The distribution of community outbreaks shows seasonal patterns along certain latitude, temperature and humidity, that is, similar to the behaviour of seasonal viral respiratory tract infections. COVID-19 displays significant spread in northern mid-latitude countries with an average temperature of 5–11°C and low humidity. Vitamin D deficiency has also been described as pandemic, especially in Europe. Regardless of age, ethnicity and latitude, recent data showed that 40 % of Europeans are vitamin D deficient (25-hydroxyvitamin D (25(OH)D) levels <50 nmol/l), and 13 % are severely deficient (25(OH)D < 30 nmol/l). A quadratic relationship was found between the prevalences of vitamin D deficiency in most commonly affected countries by COVID-19 and the latitudes. Vitamin D deficiency is more common in the subtropical and mid-latitude countries than the tropical and high-latitude countries. The most commonly affected countries with severe vitamin D deficiency are from the subtropical (Saudi Arabia 46 %; Qatar 46 %; Iran 33·4 %; Chile 26·4 %) and mid-latitude (France 27·3 %; Portugal 21·2 %; Austria 19·3 %) regions. Severe vitamin D deficiency was found to be nearly 0 % in some high-latitude countries (e.g. Norway, Finland, Sweden, Denmark and Netherlands). Accordingly, we would like to call attention to the possible association between severe vitamin D deficiency and mortality pertaining to COVID-19. Given its rare side effects and relatively wide safety, prophylactic vitamin D supplementation and/or food fortification might reasonably serve as a very convenient adjuvant therapy for these two worldwide public health problems alike.

Nutrihealth Study: Seasonal Variation in Vitamin D Status Among the Slovenian Adult and Elderly Population

Several studies conducted around the world showed substantial vitamin D insufficiency and deficiency among different population groups. Sources of vitamin D in the human body include ultraviolet B (UVB)-light-induced biosynthesis and dietary intake, but people's diets are often poor in vitamin D. Furthermore, in many regions, sun exposure and the intensity of UVB irradiation during wintertime are not sufficient for vitamin D biosynthesis. In Slovenia, epidemiological data about vitamin D status in the population were investigated through a national Nutrihealth study-an extension to the national dietary survey SI.Menu (2017/18). The study was conducted on a representative sample of 125 adult (18-64 years) and 155 elderly (65-74 years old) subjects, enrolled in the study in different seasons. Their vitamin D status was determined by measuring the serum 25-hydroxy-vitamin D (25(OH)D) concentration. Thresholds for vitamin D deficiency and insufficiency were 25(OH)D levels below 30 and 50 nmol/L, respectively. Altogether, 24.9% of the adults and 23.5% of the elderly were found to be vitamin D deficient, while an insufficient status was found in 58.2% and 62.9%, respectively. A particularly concerning situation was observed during extended wintertime (November-April); vitamin D deficiency was found in 40.8% and 34.6%, and insufficient serum 25(OH)D levels were observed in 81.6% and 78.8%, respectively. The results of the study showed high seasonal variation in serum 25(OH)D levels in both the adult and elderly population, with deficiency being especially pronounced during wintertime. The prevalence of this deficiency in Slovenia is among the highest in Europe and poses a possible public health risk that needs to be addressed with appropriate recommendations and/or policy interventions.

Prevalence of hypovitaminosis D in postmenopausal women: a systematic review

BACKGROUND

Hypovitaminosis D is considered a global public health issue. Knowledge of its true dimensions will allow us to design interventions and plan preventive measures that can have a significant impact on human health.

OBJECTIVES

The aim of this study was to evaluate the prevalence of hypovitaminosis D, defined as a serum 25-hydroxyvitamin D concentration < 30 ng/ml, in postmenopausal women around the world, as well as to identify the potential associated factors.

METHODS

A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses recommendations. Specific search terms were consulted in Medline, Excerpta Medica, and Latin-American and Caribbean Health Sciences Literature databases, with no restriction for the year or language of publication.

RESULTS

Of 451 studies initially identified, 32 were selected for analysis. Collectively, those 32 studies evaluated 21,236 postmenopausal women, of whom 16,440 (77.4%) had serum 25-hydroxyvitamin D concentrations < 30 ng/ml. The reported prevalence of hypovitaminosis D ranged from 29% (in the United States) to 99.4% (in China). In six of the studies, the prevalence was above 90%.

CONCLUSIONS

If the criterion is the 30 ng/ml cut-off point, the majority of postmenopausal women in the world could be classified as having hypovitaminosis D. Among the studies evaluated, the lowest prevalence reported was nearly 30%. Neither latitude, region of the world, nor laboratory methodology were found to be associated with the prevalence of hypovitaminosis D.

Current vitamin D status in European and Middle East countries and strategies to prevent vitamin D deficiency: a position statement of the European Calcified Tissue Society

Vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D) <50 nmol/L or 20 ng/mL) is common in Europe and the Middle East. It occurs in <20% of the population in Northern Europe, in 30-60% in Western, Southern and Eastern Europe and up to 80% in Middle East countries. Severe deficiency (serum 25(OH)D <30 nmol/L or 12 ng/mL) is found in >10% of Europeans. The European Calcified Tissue Society (ECTS) advises that the measurement of serum 25(OH)D be standardized, for example, by the Vitamin D Standardization Program. Risk groups include young children, adolescents, pregnant women, older people (especially the institutionalized) and non-Western immigrants. Consequences of vitamin D deficiency include mineralization defects and lower bone mineral density causing fractures. Extra-skeletal consequences may be muscle weakness, falls and acute respiratory infection, and are the subject of large ongoing clinical trials. The ECTS advises to improve vitamin D status by food fortification and the use of vitamin D supplements in risk groups. Fortification of foods by adding vitamin D to dairy products, bread and cereals can improve the vitamin D status of the whole population, but quality assurance monitoring is needed to prevent intoxication. Specific risk groups such as infants and children up to 3 years, pregnant women, older persons and non-Western immigrants should routinely receive vitamin D supplements. Future research should include genetic studies to better define individual vulnerability for vitamin D deficiency, and Mendelian randomization studies to address the effect of vitamin D deficiency on long-term non-skeletal outcomes such as cancer.

Vitamin D Levels of Outpatients Admitted to a University Hospital in the Marmara Region of Turkey Over 3 Years

BACKGROUND

Vitamin D regulates calcium and phosphorus metabolism, and it is essential for bone formation. Several factors can affect vitamin D levels in plasma. In present study we compare vitamin D levels of outpatients, who admit to Maltepe University Hospital between 2011 and 2013 and had vitamin D measurements regarding gender, age, and season.

METHODS

Hospital records were evaluated to identify the outpatients with vitamin D levels and their gender, age, and vitamin D levels and the seasons of measurements were recorded.

RESULTS

Data of 4860 subjects (74% female) were analyzed and 69.2% were between 18-64 years old. Vitamin D levels were as follows: 43.1% ≤ 10 ng/mL, 31.9% between 10 ng/mL and 20 ng/mL, 16.1% between 20 ng/mL and 30 ng/mL, and only 8.9% ≥ 30 ng/mL. The number of females with vitamin D levels < 10 ng/mL was significantly higher than that of males, while the number of males with vitamin D levels between 10 ng/mL and 20 ng/mL was significantly higher than that of females (P = 0.001) for each of the individuals, 6.2% and 11.1% had sufficient levels in winter and summer, respectively. Overall, it was observed that 6.6% of individuals between 18-44 years old, 8.2% of individuals between 45-64 years old and 10.3% of individuals over 65 years old had vitamin D levels > 30 ng/mL.

CONCLUSIONS

The prevalence of vitamin D deficiency in outpatients of Maltepe University Hospital in Marmara region was 75% (< 20 ng/mL).

The Role of Vitamin D in Inflammatory Bowel Disease - Assessing Therapeutic and Preventive Potential of Supplementation and Food Fortification

Inflammatory bowel diseases are a group of chronic inflammatory conditions that affect gastrointestinal tract due to inapt and continuous immune activation in response to a myriad of predisposing factors (most notably genetics, environmental impact and gut microbiota composition). It has been shown that vitamin D status can also play a role in the disease pathogenesis, as its deficiency is commonly observed in two major forms of inflammatory bowel diseases - Crohn's disease and ulcerative colitis. Mounting evidence supports the concept of intricate relationship between gut dysbiosis and vitamin D metabolism, while suboptimal levels of this vitamin have been linked to increased clinical disease relapse rates, inadequate response to drugs, as well as decreased quality of life in patients with Crohn's disease and ulcerative colitis. Consequently, the pertinent question is whether increased vitamin D supplementation and (on a population level) food fortification may bring significant benefit to the affected individuals. In this short review we discuss the synthesis, functions, status and food sources of vitamin D, appraise biotechnological facets of vitamin D status analysis and food fortification, and concentrate on novel developments in the field that describe its influence on intestinal microbiota and inflammatory bowel disease.

Association between vitamin D intake and bone mineral density in Koreans aged ≥ 50 years: analysis of the 2009 Korea National Health and Nutrition Examination Survey using a newly established vitamin D database

BACKGROUND/OBJECTIVES

Vitamin D plays an important role in skeletal growth and maintenance and in the prevention of various diseases. We investigated the relationship between vitamin D intake and bone mineral density (BMD) in Korean adults aged ≥ 50 years using the 2009 Korea National Health and Nutrition Examination Survey data.

SUBJECTS/METHODS

This study was conducted in 1,808 subjects aged ≥ 50 years with BMD data in Korea. Dietary vitamin D levels were assessed by the 24-hour recall method. BMD was measured using dual-energy X-ray absorptiometry. We investigated general characteristics and the association between these characteristics, vitamin D status, and BMD.

RESULTS

Vitamin D intake was significantly lower in the osteoporosis group among women (P < 0.05). Among all subjects, the higher the serum 25(OH)D concentration, the higher the whole-body total BMD (WBT-BMD), femoral total hip BMD, and femoral neck BMD (P < 0.01). In the serum vitamin D-deficient group of both the total population and women, serum 25(OH)D concentration was associated with WBT-BMD (P < 0.05). Among women with a calcium intake < 537.74 mg/day, BMD of those with a vitamin D intake > 2.51 µg/day (average intake of women) was higher than that of women with a vitamin D intake ≤ 2.51 µg/day (P < 0.001).

CONCLUSIONS

Korean adults should increase their BMD by increasing serum 25(OH)D concentration. Furthermore, increasing vitamin D intake could improve BMD, especially in Korean women who consume less calcium than the estimated average requirement.

Vitamin D Status and Analysis of Specific Correlates in Preschool Children: A Cross-Sectional Study in Southern Croatia

Vitamin D deficiency is a globally important problem, particularly in children, but there is a lack of information regarding this deficiency in preschool children from southeastern Europe. This study aimed to establish the levels of 25-hydroxyvitamin D (25(OH)D) and associations of gender, time spent outdoors, physical activity (PA), and body mass index (as predictors) with the 25(OH)D level (outcome) in healthy preschool children. The participants were preschoolers (all 5⁻6 years of age) from southern Croatia. All the participants were tested during their mandatory medical examination 6⁻7 months prior to school enrollment. The PA was obtained using the preschool-age physical activity questionnaire (Pre-PAQ), which categorizes PA into five levels (from sedentary to vigorous PA). The prevalence of 25(OH)D deficiency was high: 58% of the children had 25(OH)D levels of <50 nmol/L (deficiency), and an additional 29% had an insufficient level of 25(OH)D (50⁻75 nmol/L). Boys had higher levels of 25(OH)D than girls. A multinomial regression using 25(OH)D categories as the outcome and a sufficient level (>75 nmol/L) as the reference value identified gender as the only significant predictor of 25(OH)D status, with boys being at lower risk for 25(OH)D deficiency than girls. These results showed a high prevalence of 25(OH)D deficiency in preschoolers from the southern part of Croatia, which is additionally alarming based on the geographical position of the studied region (42° N) and its high number of sunshine hours (>2600 h per year). Future studies examining other potential correlates of 25(OH)D in the region are warranted.

The Possibility of Applying the Vitamin D Brief Food Frequency Questionnaire as a Tool for a Country with No Vitamin D Data in Food Composition Tables

Although the role of vitamin D is well known, the possibility of assessing its intake may be constricted in countries with no vitamin D data in food composition tables, as in the case of Croatia. The aim of the presented study was to adjust the VIDEO-FFQ (Vitamin D Estimation Only-Food Frequency Questionnaire), previously validated in Poland, to the Croatian population and to assess the validity and reproducibility of the adjusted Cro-VIDEO-FFQ (Croatian-VIDEO-FFQ). The study involved a group of Croatian women aged 20⁻30 and the Polish questionnaire was adjusted for a population due to similarities of the nutritional habits between countries. 106 individuals were recruited and 63 completed all the stages of the study. Participants conducted a 3-day dietary record and filled out the Cro-VIDEO-FFQ1 (first stage), as well as the same questionnaire (Cro-VIDEO-FFQ2) 6 weeks after (second stage). The following vitamin D intakes were observed in the studied group: 1.9 µg (0.2⁻8.0 µg) for 3-day dietary record, 3.3 µg (1.1⁻10.6 µg) for Cro-VIDEO-FFQ1, 3.6 µg (1.4⁻7.8 µg) for Cro-VIDEO-FFQ2. The Bland-Altman indexes in assessment of validity and reproducibility were 4.8% and 6.3%, respectively, with mean differences of 0.55 µg and 0.12 µg, as well as limits of agreement -0.91⁻2.01 µg and -0.44⁻0.69 µg. The kappa coefficient indicated a fair agreement for validity (0.21) and substantial for reproducibility (0.62), while correlations were significant (p = 0.0027, r = 0.37 for validity; p < 0.0001, r = 0.80 for reproducibility). It was observed that VIDEO-FFQ may be adjusted as a simple tool to assess vitamin D intake in a population with no vitamin D data in food composition tables, while Cro-VIDEO-FFQ may be a valid tool for nutritional assessment in Croatia.

Vitamin D Supplementation and Survival in Metastatic Colorectal Cancer

BACKGROUND

Some studies have demonstrated that higher baseline plasma levels of 25-hydroxivitamin D [25(OH)D] are associated with a significant reduction in colorectal cancer (CRC) incidence. Patients with metastatic CRC (mCRC) tend to be vitamin D insufficient, but the effect of vitamin D on the survival of mCRC patients still remains uncertain. In this study, we evaluated the association between cholecalciferol 2,000 IU daily supplementation and survival of mCRC patients.

METHODS

Seventy-two patients with mCRC were included. Seventy-one patients with 25(OH)D levels <75 nmol/l were randomized to receive standard chemotherapy or standard chemotherapy with cholecalciferol 2,000 IU daily. The primary endpoint was overall survival (OS) and the secondary endpoint was progression-free survival (PFS). The follow-up period was 46 mo.

RESULTS

All but one patient (98.6%) was vitamin D insufficient. There was no statistically significant difference in OS or PFS between those who received vitamin D supplements and controls.

CONCLUSIONS

The majority of patients with mCRC are vitamin D insufficient at the time of diagnosis. In our study, adding 2,000 IU of cholecalciferol daily for 2 yr to standard chemotherapy did not show any benefit in OS or PFS.

Nationality, Gender, Age, and Body Mass Index Influences on Vitamin D Concentration among Elderly Patients and Young Iraqi and Jordanian in Jordan

Vitamin D is necessary for maintaining and regulating calcium levels; thus, insufficiency of vitamin D increases the risk of many chronic diseases. This study aimed to examine vitamin D levels among Jordanian and Iraqi volunteers and find the relation between vitamin D level and lipid profile patients. Vitamin D levels were evaluated using enzyme-linked immunosorbent assay. For young healthy group subjects, vitamin D levels were 20.60 ± 5.94 ng/mL for Jordanian and 27.59 ± 7.74 ng/mL for Iraqi. Vitamin D concentrations for young males and females were 25.82 ± 8.33 ng/mL and 21.95 ± 6.39 ng/mL, respectively. Females wearing hijab were 20.87 ± 6.45 ng/mL, while uncovered females were 23.55 ± 6.04 ng/mL. For >40 years Iraqi subjects, vitamin D level for healthy was 29.78 ± 9.49 ng/mL and 23.88 ± 7.93 ng/mL for hyperlipidemic subjects. Vitamin D levels for overweight and obese healthy groups were significantly higher (P < 0.050) than those for the hyperlipidemic patients groups. Vitamin D levels for males were significantly higher than females and were significantly higher for healthy than those hyperlipidemic Iraqi patients. These findings showed that vitamin D levels are affected by age, nationality, gender, and health statues and highlight the importance of vitamin D supplementation for groups with low levels particularly old, hijab wearing females, and hyperlipidemic groups.

Wintertime surgery increases the risk of conversion to hip arthroplasty after internal fixation of femoral neck fracture

The study demonstrates that wintertime surgeries are associated with impaired fracture healing and increases the risk of conversion to hip arthroplasty after osteosynthesis of femoral neck fracture. Furthermore, the results raise the possibility of association between seasonal changes in vitamin D levels and impaired fracture healing of femoral neck fracture.

INTRODUCTION

Although the changes of vitamin D level and calcitropic hormones influencing bone metabolism are seasonal, the effect of seasons on hip fracture healing is unknown. We assessed the effects of seasonal periodicity on conversion to hip arthroplasty after primary osteosynthesis of femoral neck fracture.

METHODS

This nationwide retrospective observational cohort study involved 2779 patients aged ≥ 60 years who underwent internal screw fixation for primary femoral neck fracture and were discharged in 2000. Cases requiring conversion to arthroplasty during the 8-year follow-up derived from the Hungarian health insurance database were registered. Risk factors assessed included sex, age, fracture type, season of primary surgery and surgical delay. Competing-risks regression analysis was used for data analyses.

RESULTS

During the observation period, 190 conversions to hip arthroplasty (6.8%) were identified, yielding an overall incidence of 19.5 per 1000 person-years. The crude incidence rates of conversions after osteosynthesis in winter, spring, summer and fall were 28.6, 17.8, 16.9 and 14.7 per 1000 person-years, respectively. Besides younger age, female sex and intracapsular fracture displacement, wintertime primary osteosynthesis significantly increased the risk of conversion (fall vs. winter, hazard ratio (HR): 0.50, 95% confidence interval [95% CI 0.33-0.76]; spring vs. winter, HR: 0.63, [95% CI 0.44-0.92]; summer vs. winter, HR: 0.62, [95% CI 0.42-0.91]).

CONCLUSIONS

Our study demonstrate that wintertime primary osteosynthesis increases the risk of conversion surgeries. The results may help improving the outcome of primary fixation of femoral neck fractures.

Vitamin D serum level, disease activity and functional ability in different rheumatic patients

BACKGROUND

The aim of the study was to determine the serum vitamin D levels in patients with psoriatic arthritis (PsA) and compare it with patients with rheumatoid arthritis (RA) and with osteoarthritis (OA), as well as to explore the relationship of the vitamin D level with indices of disease activity and functional ability in a real-life setting in a South-European country.

METHODS

In a cross-sectional study, 120 adult patients with established diagnosis of PsA, RA and OA were consecutively enrolled. Serum 25-hydroxyvitamin D and intact parathyroid hormone were determined. Parameters of disease activity and functional ability were obtained using standard instruments.

RESULTS

Serum vitamin D insufficiency (≤ 75 nmol/L) was found in 74% of patients with PsA, 94% patients with RA and 97% of patients with OA, whereas vitamin D deficiency (≤ 25 nmol/L) was found in 13% of patients with PsA, 39% of patients with RA and in 38% of patients with OA. Compared with RA, patients with PsA had significantly higher serum vitamin D (P = 0.002), and when controlling for age and gender, their serum vitamin D level was significantly associated with disease activity and functional activity.

CONCLUSIONS

In the group of rheumatic patients, a high prevalence of serum vitamin D insufficiency/deficiency was found regardless of the type of arthritis. Patients with PsA might have higher levels of vitamin D than patients with RA, and this was associated with disease activity and functional ability. The results of this study indicate that prophylactic supplementation with vitamin D might be recommended for all rheumatic patients.

Vitamin D status and seasonal changes in plasma concentrations of 25-hydroxyvitamin D in office workers in Ankara, Turkey

BACKGROUND

Lack of sun exposure is one of the primary causes of epidemic vitamin D deficiency worldwide. The aim of this study was to investigate vitamin D status and seasonal changes in summer and winter in office workers.

METHODS

This study was conducted in Ankara located at 39° 52' 30" N, 32° 52' E. The study consisted of 118 premenopausal women and men aged between 21 and 52 years-old. Seasonal changes were evaluated in August and February. Fasting serum was obtained for intact parathyroid hormone (iPTH) and 25-hydroxyvitamin D (25OHD). Additional data were collected by a questionnaire that enquired about age, weight, height, wearing style, dietary calcium intake and sunlight exposure. Serum 25OHD concentration was measured using a precise HPLC assay. Low vitamin D status was defined as a 25OHD concentration less than 30 ng/mL.

RESULTS

Mean serum 25OHD concentration in summer was 28.4±10.4 ng/mL and 13.8±6.6 ng/mL in winter (p<0.001). 35.6% of the subjects were vitamin D insufficient in summer and 12.7% in winter (p<0.001) while 31.5% were vitamin D deficient in summer and 83.9% in winter (p<0.001). A significant increase in iPTH levels (33.1±15.9 pg/mL vs 49.6±24.3 pg/mL, p<0.001) was observed throughout the seasonal change. No significant association was found between 25OHD levels and iPTH, body mass index, age and sun exposure index (p>0.05 for all) in both seasons.

CONCLUSION

Vitamin D deficiency is very prevalent in office workers even in summer time and this should be accepted as a public health problem.

Does vitamin D status affect the attainment of in-hospital functional milestones after total hip arthroplasty?

Our study aims to identify the prevalence of low vitamin D status in patients undergoing total hip arthroplasty (THA) and to evaluate the association between serum vitamin D level and the attainment of in-hospital functional milestones. We collected data from patients who underwent THA and had preoperative serum vitamin D (serum 25-hydroxy vitamin D) levels measured. From 200 patients, 79 (39.5%) had low serum vitamin D (serum 25-hydroxy vitamin D <32 ng/mL). There were no associations between serum vitamin D level and the attainment of in-hospital functional milestones as well as length of hospital stay or perioperative complications after THA. Because low vitamin D status did not compromise the short-term functional outcomes after THA, surgery need not be delayed, but low vitamin D levels should be corrected once identified.

Worldwide vitamin D status

The aim of the present study is to summarize existing literature on vitamin D levels in adults in different continents and different countries worldwide. The best determinant of vitamin D status is the serum concentration of 25-hydroxyvitamin D (25(OH)D). Most investigators agree that serum 25(OH)D should be higher than 50 nmol/l, but some recommend higher serum levels. Traditional risk groups for vitamin D deficiency include pregnant women, children, older persons, the institutionalized, and non-western immigrants. This chapter shows that serum 25(OH)D levels are not only suboptimal in specific risk groups, but also in adults in many countries. Especially, in the Middle-East and Asia, vitamin D deficiency in adults is highly prevalent.