Fortification with vitamin D: Comparative study in the Saudi Arabian and US markets

Vitamin D Knowledge and Awareness Is Associated with Physical Activity among Adults: A Cross-Sectional Survey

The relation between knowledge and awareness of vitamin D (VD) and physical activity in adults has not been well studied. The present cross-sectional study aims to demonstrate this relation among adults living in Saudi Arabia. A total of 774 adults participated and were stratified based on self-reports of whether they were physically active (PA group, N = 562) or not (non-PA, N = 212). The prevalence of VD awareness and its health effects were significantly higher in the PA group compared with their counterparts (97 vs. 93.4%; p = 0.02 and 92.3 vs. 81.6%; p < 0.001, respectively). Sunlight was the preferred overall source of VD among the PA group (91.1%) followed by food, supplements, and fortified foods. Sardine, salmon, oily fish (63.7%) and eggs (54.6%) were reported as good dietary sources. Other positive attitudes, represented by taking supplement or multivitamins (51.2%), high sun exposure (33.1%), and daily duration of exposure to sunlight (15−30 min; 53.4%) were higher in the PA than the non-PA group (p values < 0.05). The body parts exposed to the sun among the PA group were arms (67.1%), hands (64.1%), face and hands (62.5%), legs (58.5%), and face (53.2%), while sunscreen cream (47.2%) was their preferred sun-protection method. High levels of knowledge and positive attitudes were reported by the PA group compared with the non-PA group in regard to walking outdoors for sun exposure (80.6 vs. 62.7%; p < 0.001). Information about good dietary sources, the role of VD in human health, associated diseases, positive attitudes to sun exposure, and the use of supplements or multivitamins were among the determinants of VD knowledge and awareness. In conclusion, VD knowledge and awareness are positively associated with self-reported physical activity in adults. Further objective classifications of PA may strengthen the results of the present investigation.

Establishing the Prevalence of Osteomalacia in Arab Adolescents Using Biochemical Markers of Bone Health

Nutrition-acquired osteomalacia is a bone mineralization disorder associated with dietary calcium and/or solar vitamin D deficiency, risk factors considered common in the Middle Eastern region. Establishing less invasive, cheap, and widely available diagnostic markers for this underdiagnosed entity is essential, in particular for screening in high-risk groups. This study assessed the prevalence of biochemical osteomalacia in Arab adolescents. In this cross-sectional study performed between September 2019 and March 2021, adolescents aged 12−17 years from 60 different secondary and preparatory year schools in Riyadh, Saudi Arabia were included. Anthropometrics and fasting blood samples were collected. Biochemical osteomalacia was defined as any two of the following four serum markers of hypomineralization, namely low 25 hydroxyvitamin D (25OHD < 30 nmol/L), high alkaline phosphatase (ALP), low calcium (Ca), and/or inorganic phosphorous (Pi). A total of 2938 Arab adolescents [1697 girls; mean age (years) 14.8 ± 1.8; 1241 boys; mean age 15.1 ± 1.6] were recruited. Vitamin D deficiency was noted in 56.2% (n = 953) of girls and 27.1% (n = 336) of boys (p < 0.001). The overall prevalence of biochemical osteomalacia was 10.0% (n = 295/2938) and was higher in girls than boys (14.7% vs. 3.6%, p < 0.001). The prevalence of low serum Ca and/or Pi was also higher in girls than in boys (24.2% vs. 12.5%, respectively, p < 0.001), as well as elevated ALP (5.1% vs. 1.5%, p < 0.001). Overall, girls were 4.6 times (95% CI 3.3−6.4) more likely to have biochemical osteomalacia than boys. Screening of apparently healthy Arab adolescents revealed a high prevalence of deranged mineralization markers suggestive of biochemical osteomalacia, which was significantly more common in girls than boys and was likely associated with Arab traditional clothing and diet. The proposed combination of typically altered mineralization markers for the diagnosis of osteomalacia is, at best, suggestive until further comparisons with established diagnostic tools (histological analysis of bone biopsies) are conducted.

The Prevalence of Vitamin and Mineral Deficiencies and High Levels of Non-Essential Heavy Metals in Saudi Arabian Adults

Although the micronutrient status of a population is of high national priority, as it critically impacts public health, limited data is available for quantifying the micronutrient status in Saudi Arabia. We aimed to provide comprehensive, epidemiological, descriptive data regarding micronutrient levels in Saudi adults. This cross-sectional study included 3432 adults aged ≥18 years (mean age, 37.7 ± 11.7 years; women, 51.2%) across all 13 Saudi administrative regions (March 2019-November 2021). Laboratory data for 14 micronutrients (8 vitamins, 4 minerals, and 2 nonessential heavy metals) were characterized using descriptive analysis. Vitamin D deficiency (64.3%) was the most prevalent, followed by vitamin B2 (44.9%) and A (9.6%) deficiencies. Among minerals, iron deficiency was the most prevalent (23.2%), followed by zinc (15.3%) and copper (8.7%) deficiencies. Most Saudi adults exhibited normal arsenic (99.7%) and mercury (99.9%) levels. Men exhibited significantly higher vitamin B2, B9, and D deficiencies than women, while women exhibited higher vitamin A, B12, iron, and zinc deficiencies than men. Younger adults demonstrated a significantly higher prevalence of vitamin D and iron deficiencies, whereas older adults exhibited a higher prevalence of vitamin B1 and magnesium deficiencies. As micronutrient deficiencies are a public health concern, health policies and programs need to be developed and implemented to address them.

The use of finite mixture models to examine the serum 25(OH)D levels among Saudis

BACKGROUND

Recorded serum 25(OH)D in survey data varies with observed and unobserved respondent characteristics. The aim of this study was to expose latent population sub-groups and examine variation across groups regarding relationships between serum 25(OH)D and observable characteristics.

METHODS

This study explored the role of unobserved heterogeneity on associations between surveyed 25(OH)D and various factors using a sample (n = 2,641) extracted from the Saudi Health Interview Survey (2013). Linear regression and finite mixture models (FMM) were estimated and compared. The number of latent classes in the FMM was chosen based on BIC score.

RESULT

Three latent classes were identified. Class I (39.82%), class II (41.03%), and class III (19.15%) with mean 25(OH)D levels of 22.79, 34.88, and 57.45 ng/ml respectively. Distinct patterns of associations with nutrition, behaviour and socio-demographic variables were recorded across classes that were not revealed in pooled linear regression.

CONCLUSION

FMM has the potential to provide additional insights on the relationship between 25(OH)D levels and observable characteristics. It should be more widely considered as a method of investigation in this area.

Vitamin D Deficiency and Associated Risk Factors in Women from Riyadh, Saudi Arabia

Vitamin D deficiency is an epidemic public health problem worldwide. It is common in the Middle East and is more severe in women. This cross-sectional study was conducted to assess vitamin D deficiency and associated risk factors in women living in Riyadh, Saudi Arabia. Serum 25-hydroxyvitamin D (25(OH)D) was measured in 166 women aged 30-65 years. Socio-demographic, lifestyle and health status characteristics, as well as intake of selected dietary supplements, were collected. Weight and height were measured. Vitamin D deficiency (25(OH)D < 20 ng/mL) was reported in 60.2% of participants. Mean of serum 25(OH)D was 20.7 ng/mL. Older age and taking the supplements of vitamin D, multi-vitamins or calcium were identified as factors that associated with a lower risk of hypovitaminosis D. A national strategy is needed to control a hypovitaminosis D crisis in Saudi Arabia. This could be accomplished by raising public awareness regarding vitamin D, regulating and enhancing vitamin D fortification and supplementation and screening vitamin D status among women at high risk.

Vitamin D deficiency and glycemic control among patients with type 2 diabetes mellitus in Jazan City, Saudi Arabia

Background: The prevalence of vitamin D deficiency (VDD) is predicted to be high in patients with type 2 diabetes mellitus (T2DM), but the exact figure is not known in Jazan, Saudi Arabia. Emerging data suggests that VDD plays a role in glycemic control. The aim of this study was to measure the prevalence of VDD among T2DM patients and to investigate its association with patients' characteristics and glycemic control in Jazan. Methods: This is an analytical cross-sectional study which recruited 309 patients with T2DM randomly from primary health care centers in Jazan. Logistic regression analysis was conducted to determine the VDD predictors and to examine the association of VDD and glycemic control. Results: The VDD prevalence was found to be 60.8% in patients with T2DM. Age, gender, diabetic retinopathy (DR), dyslipidemia, glycemic control, and obesity were significantly associated with VDD, and all except obesity were independent predictors of VDD. There was a significant negative correlation between 25-hydroxyvitamin D and HbA1c. VDD was a significant independent predictor of poor glycemic control after adjustment for hypertension, DR, diabetic neuropathy, type of diabetes medication, diabetes duration, and education level. Conclusion: In this Saudi Arabian population, VDD is highly prevalent in people with T2DM and is associated with poor glycemic control. Health education targeting patients with T2DM and national strategies regarding vitamin D fortification are needed to prevent VDD in Saudi Arabia. Earlier VDD diagnosis by health care providers may help to improve the outcome for patients with T2DM. Establishing the causal association between VDD and glycemic control and clarifying the biological role of vitamin D in T2DM are important aims for future studies.

Vitamin D Supplementation Modestly Reduces Serum Iron Indices of Healthy Arab Adolescents

Vitamin D deficiency has been shown to affect iron status via decreased calcitriol production, translating to decreased erythropoiesis. The present study aimed to determine for the first time whether vitamin D supplementation can affect iron levels among Arab adolescents. A total of 125 out of the initial 200 Saudi adolescents with vitamin D deficiency (serum 25(OH)D < 50 nmol/L) were selected from the Vitamin D-School Project of King Saud University in Riyadh, Saudi Arabia. Cluster randomization was done in schools, and students received either vitamin D tablets (1000 IU/day) (N = 53, mean age 14.1 ± 1.0 years) or vitamin D-fortified milk (40IU/200mL) (N = 72, mean age 14.8 ± 1.4 years). Both groups received nutritional counseling. Anthropometrics, glucose, lipids, iron indices, and 25(OH)D were measured at baseline and after six months. Within group analysis showed that post-intervention, serum 25(OH)D significantly increased by as much as 50%, and a parallel decrease of −42% (p-values <0.001 and 0.002, respectively) was observed in serum iron in the tablet group. These changes were not observed in the control group. Between-group analysis showed a clinically significant increase in serum 25(OH)D (p = 0.001) and decrease in iron (p < 0.001) in the tablet group. The present findings suggest a possible inhibitory role of vitamin D supplementation in the iron indices of healthy adolescents whose 25(OH)D levels are sub-optimal but not severely deficient, implying that the causal relationship between both micronutrients may be dependent on the severity of deficiency, type of iron disorder, and other vascular conditions that are known to affect hematologic indices. Well-designed, randomized trials are needed to confirm the present findings.

The association of serum 25-OH vitamin D with asthma in Saudi adults

The study aimed to assess the differences and associations of serum 25 (OH)D levels in Saudi adults with and without asthma. A total of 1070 Saudi adults aged 22 to 28 years (359 with known asthma and 711 matched nonasthmatic controls) were selected randomly from the Riyadh Cohort, Saudi Arabia. Serum 25(OH)D serum levels were measured. Asthma diagnosis was taken from questionnaires. In all participants, 359 (33.6%) were known asthmatic and 711 (66.5%) were nonasthmatic. The overall incidence of vitamin D deficiency (serum 25(OH)D <25 nmol/L) was 29.6% in controls and 35.6% in asthma group (P = .01). The asthma group have a significantly lower serum 25(OH)D than the control group (P = .01) but lost significance after adjusting for age, body mass index (BMI), and sex. Nonasthmatic and asthmatic females had a higher incidence of vitamin D deficiency (33% and 46%) than nonasthmatic and asthmatic males (17% and 33%). Vitamin D deficiency is significantly high among Saudi adults with asthma, but more so among women. Whether vitamin D deficiency exacerbates asthma attack remains to be proven in this population.

Maintenance Dose of Vitamin D: How Much Is Enough?

Background

It is still unclear the ideal vitamin D dosage once the deficiency and insufficiency is treated. Once deficiency was corrected we prospectively treated patients with 2,000 IU of vitamin D3 to check whether this dosage is enough to keep them above the 30 ng/mL of 25-hydroxy-vitamin D (25[OH]D).

Methods

One hundred and thirty-five Saudi Arabian men and women treatment naïve for the vitamin D deficiency and insufficiency were part of this study. History and clinical examination were done to rule out any metabolic bone disease. Weight and height was taken to calculate the body mass index (BMI). Patients who were vitamin D deficient (≥30 ng/mL), a standard treatment of 50,000 IU of vitamin D3 weekly for 3 months, a blood test for the vitamin D levels at the end of 3 months, maintenance dose of 2,000 IU of vitamin D3 for 3 months and a third blood sample after 3 months.

Results

The data for 128 patients was available for analysis. The average age was 44.95±12.97 years with the mean BMI of 29.60±2.59 kg/m². The baseline 25(OH)D level was 13.16±3.30 ng/mL. The increase in the level of 25(OH)D on 50,000 IU weekly was significant from 13.16±3.3 ng/mL to 36.97±4.67 ng/mL (P<0.001) and then 2,000 IU daily for next 3 months, the level of 25(OH)D dropped top 20.38±5.42 ng/mL (P<0.001).

Conclusions

Our study indicates that the maintenance dose of 2,000 IU of vitamin D is not enough for patients to keep the 25(OH)D levels above 30 ng/mL.

Efficacy of different modes of vitamin D supplementation strategies in Saudi adolescents

Vitamin D deficiency is rampant in the Middle East, even in children and adolescents. This study was designed to investigate the effects of different vitamin D repletion strategies commonly used on serum vitamin D levels of Saudi adolescents.

STUDY DESIGN

A 6-month multi-center, controlled, clinical study, involving 34 schools in the central region of Riyadh, Saudi Arabia. Different strategies of vitamin D supplementation were tested (200 ml fortified milk of different brands or vitamin D tablet (1,000IU). Anthropometrics were taken and fasting blood samples withdrawn at baseline and after intervention for the quantification of serum glucose, lipid profile and 25(OH) vitamin D. A significant increase in 25(OH)D level was observed in subjects supplemented with vitamin D tablet, milk brand 2 and milk brand 4, whereas subjects supplied with fortified milk brands 1 and 3 respectively, exhibited a significant decrease in 25(OH)D levels. Analysis of covariance showed that after adjusting for baseline 25(OH)D, age, gender and BMI, the mean 25(OH)D levels of children who were taking vitamin D tablet (9.1 ± 0.8 nmol/l) and milk brand 4 were significantly higher (7.3 ± 1.1 nmol/l) than children taking milk brand 2 (1.6 ± 1.0 nmol/l). Subjects supplied with milk brands 1 and 2 exhibited a significant increase in total cholesterol level, while it dropped significantly in subjects taking milk brand 3, while no changes were observed in other groups. Different strategies in vitamin D supplementation used in this clinical study elicited varying degrees of improvement in serum 25(OH)D level. The observed outcomes were dependent on the strategy and gender in the Saudi adolescent population, with oral tablet supplementation being favored in boys.

Age and gender differences in the prevalence and correlates of vitamin D deficiency

Younger adults and males had a higher prevalence of vitamin D deficiency compared to older participants and females. Low intake of milk, central obesity, and lack of use of vitamin D supplements were associated with vitamin D deficiency, highlighting potentially important avenues for preventive intervention.

BACKGROUND

Vitamin D deficiency is a public health concern. This study's objective was to measure the prevalence of vitamin D deficiency and determine its correlates among Saudi adults in Riyadh, Saudi Arabia.

METHODS

A cross-sectional study was conducted with 2835 Saudi males and females aged 30-75 years in 18 different primary health care centers (PHCC) in Riyadh. Detailed interviews on sociodemographic and lifestyle factors and anthropometric measurements were conducted. Serum calcium, phosphorus, parathyroid, alkaline phosphatase, and 25(OH) vitamin D were measured. Multiple logistic regression analyses were conducted.

RESULTS

The mean age (SD) of male and female participants was 43.0 (± 11.7) and 42.8 (± 10.3) years, respectively. Serum 25(OH) vitamin D assays for participants revealed that 72.0% (n = 695) of males and 64.0% (n = 1191) of females had levels < 50 nmol/L (deficiency), whereas 17.3% (n = 166) and 19.4% (n = 362), respectively, had levels of 50-75 nmol/L (insufficiency). Multivariate analyses for males revealed that lack of use of vitamin D supplements [adjusted odds ratio (aOR) = 4.0, 95% CI 1.7, 9.4], younger age [30-40 years aOR = 3.6, 95% CI 1.7, 7.3 and 41-50 years aOR = 4.2, 95% CI 2.0, 8.8], low milk intake [aOR = 1.7, 95% CI 1.0, 2.8], consumption of cola drinks [aOR = 2.0, 95% CI 1.1, 3.9], and central obesity [aOR = 1.8, 95% CI 1.0, 3.4] were associated with low vitamin D. In females, lack of use of vitamin D supplements [aOR = 3.7, 95% CI 2.8, 4.9], younger age [30-40 years aOR = 3.4, 95% CI 2.0, 5.8 and 41-50 years aOR = 2.8, 95% CI 1.6, 4.7], central obesity [aOR = 1.4, 95% CI 1.0, 2.2], and seasonal variation [aOR = 1.6, 95% CI 1.3, 2.1] had higher odds for vitamin D deficiency. Significantly lower levels were observed for men than women for mean serum 25(OH) vitamin D [42.6 (± 24.1) vs. 46.8 (± 30.5)], parathyroid hormone [5.3 (± 2.9) vs. 5.9 (± 2.7)], and phosphorus [1.1 (± 0.2) vs. 1.2 (± 0.2)], respectively; alkaline phosphatase levels [106 (± 32.8) vs. 99 (± 27.8)] [p < 0.01] were significantly higher in males than females.

CONCLUSION

Vitamin D deficiency was highly prevalent, particularly among young adults and those with central obesity. Proper fortification policy, health education, and regular screening PHCCs may help prevent and treat vitamin D deficiency.

The Prevalence of Hypovitaminosis D and Its Associated Risk Factors Among Women of Reproductive Age in Saudi Arabia: A Systematic Review and Meta-Analysis

Vitamin D deficiency is currently a worldwide epidemic. Middle Eastern countries, including Saudi Arabia, have high vitamin D deficiency prevalence, most prominently among women, despite their plentiful year-round sunshine. Previous research investigating vitamin D status among Saudi women of reproductive age (15-49 years) is scarce, and no study has used a nationally representative sample, so this review quantified overall hypovitaminosis D prevalence among women in Saudi Arabia and explored the associated risk factors. The Web of Science, Scopus, and Medline databases were searched for prior studies in Saudi Arabia exploring vitamin D status among women of reproductive age, published between January 1, 2000 and May 25, 2017. Data were extracted from the identified studies, and a random effects model meta-analysis established the overall hypovitaminosis D prevalence. The initial search yielded 223 possibly relevant articles; 13 were confirmed as eligible, with samples totaling 2877 women aged between 15 and 49 years. Meta-analysis revealed a mean serum 25-hydroxyvitamin D, 25(OH)D, level of 13.1 ng/mL (95% confidence interval [CI]: 11.6-14.6) and an overall prevalence of hypovitaminosis D, defined as 25(OH)D < 30 ng/mL, of 77.4% (95% CI: 63.2-87.3), mostly due to insufficient sunlight exposure and low dietary vitamin D intake. There is therefore a need for a national strategy to raise vitamin D levels among women in Saudi Arabia by advising them on natural vitamin D sources, and recommending the timing and duration of sun exposure, while also defining a national approach to vitamin D fortification and supplementation.

Exploring Knowledge and Attitudes about Vitamin D among Adults in Saudi Arabia: A Qualitative Study

Abstract: Vitamin D deficiency is widespread in Saudi Arabia. The aim of this study was to explore participants' knowledge about vitamin D and attitudes toward sun exposure. The study also aimed to explore the social and cultural factors that might potentially contribute to vitamin D deficiency in Saudi Arabia. Face-to-face interviews were carried out in the cities of Jeddah and Makkah between May and October 2015. The interview questions were semi-structured, and the data was analyzed using thematic analysis. Study participants showed a reasonable level of knowledge in different areas about vitamin D, including the effect of vitamin D deficiency on bone health and exposure to sunlight as the main source of vitamin D. Participants were also knowledgeable about vitamin D supplements as another source of this vitamin. Nevertheless, there was a shortage of knowledge in relation to dietary sources of vitamin D. In respect to attitudes toward sun exposure, some participants had positive attitudes toward sunlight and were willing to expose themselves to sunlight, but it was restricted to the early morning or late afternoon to avoid the heat. These participants who liked exposure to sunlight were largely exposing only their faces and hands to sunlight. Other participants had negative attitudes toward sun exposure and were avoiding sunlight. Moreover, the study participants identified several barriers to sun exposure, including hot climate, living in high-rise buildings, limited public areas allowing outdoor activities, lifestyle issues such as physical inactivity, and some religious concerns such as wearing the hijab. The study results also demonstrate that females were more enthusiastic about taking actions to improve their vitamin D status in comparison with males. Recommendations for health education interventions that increase awareness about vitamin D sources, especially food sources, are made. Also, educational interventions should focus on increasing awareness about the sufficient time of the day and duration for sun exposure to improve vitamin D status and the importance of the intake of vitamin D supplements as an affordable source to improve vitamin D status. Increasing males' awareness of the benefits of vitamin D is important to encourage them to adopt behaviors to improve vitamin D.

The relationship between serum vitamin D levels and sleep quality in fixed day indoor field workers in the electronics manufacturing industry in Korea

Background

Although recent studies have investigated the influence of vitamin D on sleep patterns, there is a lack of research on the relationship between vitamin D and sleep patterns in Korean workers. This study focused on the relationship between serum vitamin D levels and sleep in fixed day indoor field workers in the electronics manufacturing industry in Korea.

Methods

The 1472 subjects who were included in this study were selected from fixed day workers in the electronics manufacturing industry who had received a worker’s special health examination at a hospital in Changwon, South Gyeongsang Province between January 2015 and December 2015. Nighttime workers and those who showed symptoms of depression were excluded from this study. The sociodemographic and lifestyle variables of the participants were investigated, including age, sex, marital status, level of education, body mass index, smoking habits, alcohol consumption habits, and regular exercise. Work-related factors were evaluated, such as employee tenure and occupational stress. Serum 25-hydroxyvitamin D was measured as an indicator of vitamin D levels, and quality of sleep was evaluated using the Pittsburgh Sleep Quality Index (PSQI) translated into Korean.

Results

The subjects had a mean serum vitamin D level of 13.70 ± 5.93 ng/mL. Vitamin D deficiency, defined as a serum vitamin D level of <10 ng/mL, was found in 24.8% of males and significantly more frequently in females (47.6%). Poor sleep quality was reported by 19.8% of participants with serum vitamin D levels ≥10 ng/mL and by 21.7% of those with serum vitamin D levels <10 ng/mL, which was a significant difference (P = .007). Multiple logistic regression analysis adjusting for significant variables found that poor sleep quality was more likely in those with vitamin D deficiency than those with higher serum vitamin D levels (odds ratio = 1.36; 95% CI, 1.01–1.82). A comparison of serum vitamin D levels and PSQI components showed that the mean scores for subjective sleep quality, sleep latency, and sleep duration were significantly higher in the vitamin D-deficient participants, indicating that the vitamin D-deficient participants had poorer sleep quality.

Conclusions

This study investigated serum vitamin D levels in fixed day indoor field workers in the manufacturing industry in Korea and analyzed the relationship of vitamin D deficiency with sleep quality. A significant correlation was found between serum vitamin D deficiency and poor sleep quality. Based on the results of this study, sleep disorder management for workers can be improved by providing regular examinations checking their serum vitamin D levels and supplying vitamin D to workers with serum vitamin D deficiency to enhance their quality of sleep.

Knowledge and attitudes about vitamin D, and behaviors related to vitamin D in adults with and without coronary heart disease in Saudi Arabia

Background

Vitamin D deficiency is prevailing in Saudi Arabia. Recent national data indicated an inverse association between vitamin D status and coronary heart disease (CHD), which increases concerns about vitamin D deficiency as a serious public health problem. Therefore, the current study aimed to investigate whether knowledge, attitudes and behaviors related to vitamin D contribute to the prevalence of vitamin D deficiency among adults with and without CHD in Saudi Arabia.

Methods

This case-control study consisted of 130 CHD cases and 195 matched controls. The study subjects were recruited from three hospitals in Saudi Arabia. Structured interviews were completed to collect data on participants’ socio-demographics, knowledge about vitamin D, attitudes toward sun exposure, and behaviors related to vitamin D. Also, serum vitamin D levels were measured.

Results

Severe vitamin D deficiency [serum 25(OH)D < 10 ng/mL] was more prevalent in the CHD cases than in the controls (46% and 3%, respectively). The total knowledge score was higher in the controls than in the cases [2.5 (±1.8) and 1.6 (±2.2), respectively]. The cases had better attitudes toward sun exposure compared to the controls (p = 0.001); however, the controls had better attitudes toward vitamin D compared to the cases (p = 0.001). The controls had a higher consumption of multivitamin supplements than the cases (6.7% and 0.8%, respectively; p = 0.010). Similarly, the controls had a higher consumption of butter (p = 0.001), oily fish (p = 0.004), and liver (p = 0.003) than the cases; however, the cases had a significantly higher intake of milk (p = 0.001). A multivariate logistic regression showed that vitamin D deficiency [25(OH)D < 20 ng/mL] was associated with low levels of knowledge about vitamin D, with an odds ratio of 1.82 (95% CI: 1.08–3.06, P = 0.024). Vitamin D deficiency was also associated with low intake of vitamin supplements, with an odds ratio of 4.35 (95% CI: 2.12–8.92, P < 0.001).

Conclusion

The present study revealed that low levels of knowledge about vitamin D and low consumption of vitamin supplementation, including vitamin D, calcium, multivitamin, and calcium supplements with vitamin D, may have contributed to the higher prevalence of vitamin D deficiency among the CHD cases than among the controls. Further studies using a qualitative approach are crucial to explore the underlying reasons for low knowledge about vitamin D and behaviors related to vitamin D including the intake of vitamin supplementation  that may contribute to the high burden of vitamin D deficiency in the country.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4183-1) contains supplementary material, which is available to authorized users.

Vitamin D content in fortified low fat milk in Saudi Arabia

BACKGROUND

Vitamin D deficiency is common in many countries, including Saudi Arabia. Various population-level preventive measures have been implemented, including milk fortification with vitamin D.

OBJECTIVES

The main objective of the study was to determine vitamin D levels in fortified low fat cow milk on the Saudi Arabian market and to compare it with the label claims.

DESIGN

Cross-sectional study.

SETTING

Academic research center.

MATERIALS AND METHODS

Five milk batches from five major producers were purchased in five replicates from five major retail stores in Riyadh, Saudi Arabia. We used a validated liquid chromatography assay to measure vitamin D levels. All samples were producer labeled to contain 400 IU/L (10 ng/mL) vitamin D and were analyzed within the first 40% of their validity period. Intra-batch, inter-batch, and inter-producer variations were determined as a coefficient of variation.

MAIN OUTCOME MEASURES

Intra-batch, inter-batch and inter-producer variations in vitamin D level.

RESULTS

Overall, mean (SD) measured vitamin D level was 10.2 (1.6) with a range of 7.1-13.9 ng/mL. In 25 of 125 samples (20%), the vitamin D level was outside +/- 20% of the label claim (10.4% under-fortified, 9.6% over fortified). Intra-batch, inter-batch, and intra-producer variations were 1.6 -20.8%, 8.2-20.8%, and 16.1%, respectively.

CONCLUSIONS

Vitamin D content in fortified low fat cow milk on the Riyadh market matches label claim in 85% of the samples of major retailers. Variations from label claim in 15% of the samples are small and may not be clinically important.

LIMITATIONS

This study was limited to five major retailers in the Riyadh area and did not examine full-fat or non-fat milk samples.

High Prevalence of Vitamin D Deficiency among Pregnant Saudi Women

Vitamin D deficiency has emerged as a public health problem worldwide due to its important role in health and disease. The present work is intended to examine prevalence of vitamin D deficiency among pregnant Saudi women and related risk factors. A cross-sectional study was carried out at King Fahad Medical City in Riyadh, Saudi Arabia. Serum 25-hydroxy vitamin D (25(OH)D) was measured by enzyme-linked immunosorbent assay in 160 pregnant women during the first trimester of pregnancy. Socio-demographic, lifestyle and maternal characteristics were collected and vitamin D intake was assessed using a 24-h dietary recall. Weight and height were measured using standardized methods. Vitamin D deficiency (25(OH)D < 50 nmol/L) and insufficiency (25(OH)D = 50–74 nmol/L) were reported in 50% and 43.8% of the study sample, respectively. Median serum 25(OH)D concentration was 49.9 nmol/L. Adequate vitamin D intake (≥600 IU/day) was reported among only 8.1% of pregnant women. Age group, educational level, sun exposure frequency and daytime and daily practice of exercise were significantly associated with vitamin D status. Overall, vitamin D deficiency was common among pregnant Saudi women in Riyadh. Steps should be taken to address the current situation, including increased sunlight exposure, consumption of fatty fish, and vitamin D supplements.

Deficiencies Under Plenty of Sun: Vitamin D Status among Adults in the Kingdom of Saudi Arabia, 2013

BACKGROUND

Vitamin D deficiency has been correlated with several diseases and injuries including diabetes, osteoporosis, fractures, and falls. In the Kingdom of Saudi Arabia (KSA), current data on vitamin D status are lacking.

AIMS

To inform Saudi public health authorities on the current status of blood levels vitamin D deficiency, we analyzed data from the Saudi Health Interview Survey.

MATERIALS AND METHODS

The Saudi Health Interview Survey (SHIS) is a cross-sectional national multistage survey of individuals aged 15 years and above on sociodemographic characteristics, tobacco consumption, diet, physical activity, health care utilization, different health-related behaviors, and self-reported chronic conditions. A total of 10,735 participants completed a health questionnaire and were invited to the local health clinics for biomedical exams.

RESULTS

62.65% of female Saudis and 40.6% of male Saudis aged 15 years and above are deficient in vitamin D. Out of them, less than 1% males and less than 2% females consume vitamin D supplements. Women who have never married and obese individuals are more likely to be deficient in vitamin D, compared to men who were currently married and nonobese individuals. Those consuming vitamin D supplements are less likely to be deficient in vitamin D.

CONCLUSIONS

Our study showed a high prevalence of vitamin D deficiency among Saudi men and women, and the results call for an increased awareness to ensure adequate levels of vitamin D for better health in Saudi Arabia. Moreover, our findings are certainly relevant for other countries in the Gulf region or countries with similar cultures, clothing, and religions.

Dairy products consumption and serum 25-hydroxyvitamin D level in Saudi children and adults

Vitamin D deficiency is implicated in several calcium deficiency-related disease conditions. We aimed to investigate vitamin D status and its association with consumption frequencies of various dairy products in Saudi population. Subjects consisted of 820 children (327 boys; mean age 14.9 yrs and 493 girls; 14.8 yrs) and 565 adults (249 men, 27.9 yrs and 316 women 32.2 yrs). We estimated the consumption frequencies of various dairy food products (fresh milk, powdered milk, laban, yoghurt and cheese) using a qualitative food frequency questionnaire and serum level of 25-hydroxyvitamin D (25 (OH) D). Associations between variables of interest were assessed by Pearson correlation analysis. Among the study subjects, 80% boys, 90% girls, 64% men and 50% women had deficient/insufficient levels of vitamin D. Modest associations were found between mean serum 25 (OH) D concentration and fresh milk consumption in children (r=0.11) (especially in girls (r=0.12)), and overall dairy products consumption in women (r=0.12).

CONCLUSION

Results indicated widespread vitamin D deficiency in Saudi Arabian children and adults. High level of vitamin D deficiency and a lack of strong correlation between dairy product consumption and serum level of vitamin D imply a need for adequate fortification of milk and other dairy products with vitamin D.

Determinants of vitamin D deficiency among undergraduate medical students in Saudi Arabia

BACKGROUND/OBJECTIVES

The objectives of our study were to determine possible factors associated with low vitamin D levels in medical students.

SUBJECTS/METHODS

A cross-sectional study was performed among 255 first- to fifth-year male undergraduate medical students of one of the major universities in Saudi Arabia. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using electrochemiluminiscence. Multiple logistic regression analysis was performed.

RESULTS

Majority of Saudi medical students (75.2%) had 25(OH)D levels <30 nmol/l, defined as risk for deficiency by the Institute of Medicine. Multivariate analysis showed that the odds of having 25(OH)D serum levels of ⩾ 30 nmol/l were seven times higher both in students who took vitamin D (odds ratio (OR)=7.2, 95% confidence interval (CI)=1.8-29.9, P=0.006) or multivitamin supplements (OR=6.9, 95% CI=1.7-27.3, P=0.006) within 1 year. Students with a history of vitamin D testing >1 year before the study or moderate/vigorous physical activity (PA) had 4.4 (OR=4.4, 95% CI=1.7-11.4, P=0.003) and 2.7-fold (OR=2.7, 95% CI=1.3-5.3, P=0.006) higher odds of having 25(OH)D levels ⩾ 30 nmol/l, respectively. There was no significant association between 25(OH)D serum levels and average time spent outdoors per day (P=0.369) and type of clothing (long-sleeved vs short-sleeved; P=0.800).

CONCLUSIONS

Vitamin D deficiency was highly prevalent in Saudi medical students. Modifiable factors such as vitamin D intake and PA could be targeted for intervention. Further studies with standardized laboratory measurements of 25(OH)D are needed to explore the role of vitamin D testing in behavioral change, which may lead to increased serum 25(OH)D levels.

Dietary products consumption in relation to serum 25-hydroxyvitamin D and selenium level in Saudi children and adults

Vitamin D deficiency is a global health threat that has been associated with several chronic diseases. Selenium is an essential trace element because of role in major metabolic processes, immune function, thyroid hormone metabolism, male infertility, neoplasms and cardiovascular disease. We aimed to investigate for the first time in the Saudi population the association between vitamin D and selenium status with various dietary products consumption. A total of 259 children and 95 adults were included in this cross-sectional study. We estimated the consumption frequencies of various dietary food products using a qualitative food frequency questionnaire (FFQ) and also measured serum levels of 25-hydroxyvitamin D and selenium. Associations between variables of interest were assessed. Vitamin D deficiency and insufficiency were observed in 80% of the boys, 90% of the girls, 64% of men and 50% of women. Modest associations were found between mean serum 25 (OH) D concentration and consumption frequencies of fresh milk in children (r=0.11; P<0.05), more specifically in girls (r=0.12; P<0.05), and to the overall consumption of dairy products in women (r=0.12; P<0.05). Vitamin D status was also inversely associated with selenium in adults (r=-0.43; P<0.05). There was a significant correlation between delta changes of serum selenium, triglycerides and HDL levels (P-values <0.05). Vitamin D and selenium levels are modestly associated with dietary products consumption. Changes in selenium levels were associated with increased serum triglyceride levels, indicating a potential biomarker for cardiovascular risk and dyslipidemia. The widespread vitamin D deficiency observed in the present study highlight the need for adequate fortification of dairy products.

Increasing trends and significance of hypovitaminosis D: a population-based study in the Kingdom of Saudi Arabia

Vitamin D deficiency is highly prevalent in Saudi Arabia, particularly among young women and is emerging as public health threat of epidemic proportions. Prevalence of severe hypovitaminosis D is expected to rise exponentially without primary intervention. This largest study encompasses extent of vitamin D deficiency and recommendations to reduce significant health care burden.

INTRODUCTION

The aim of the study was to determine the prevalence and significance of vitamin D deficiency in Saudi population and to help develop national consensus for its prevention, screening, and management.

METHODS

This was a retrospective observational study which involved 10,709 patients, recruited from the Department of Family Medicine and Polyclinic, King Faisal Specialist Hospital and Research Center (KFSH&RC), Saudi Arabia, over a period of 5 years. The endpoints included overall status of vitamin D level and severity of vitamin D deficiency. Serum measurements included 25 hydroxyvitamin D (25(OH)D), parathormone, calcium, phosphate, alkaline phosphatase, albumin levels, eGFR levels, bone mineral density.

RESULTS

A total of 10,709 patients were analyzed; 31.4 % were males and 68.6 % were females, with a preponderance of Saudis (68.5 %) compared to non-Saudis (31.5 %). The prevalence of vitamin D deficiency was 83.6 % (31.9 % severe, 32.0 % moderate, and 19.7 % mild), when cut points of less than 25, 50, and 75 nmol/l, respectively, were used. Mean serum 25(OH)D was 44.58 ± 34.80 standard deviation (SD) nmol/l. There was significant difference in severity of vitamin D deficiency stratified by age, gender, and nationality. More females had severe 25(OH)D deficiency compared to males (35.6 vs. 23.7 %, p < 0.000). Severe 25(OH)D deficiency was markedly high among adolescents as compared to other age groups (49.2 vs. 30.9 %, p < 0.000). More Saudis were found to be vitamin D deficient compared to non-Saudis (37.2 vs. 20.3 %, p < 0.000).

CONCLUSION

The prevalence of hypovitaminosis D is significantly high among Saudi population, especially among women, despite abundant sunshine. It is a major public health concern and requires a robust health policy for vitamin D supplementation and implementation of dietary public health measures. Vitamin D screening is strongly recommended at an earlier age especially among women and children.