King Saud Medical City, King Saud University,
Riyadh, Saudi Arabia.
Email: d-sahar44 [at] hotmail.com
Background: Vitamin D is a steroid vitamin which promotes the intestinal absorption and metabolism of calcium and phosphorus. The current study aims to detect the awareness of level of vitamin D in females and to identify the risk factors of vitamin D deficiency in female students.
Methodology: This was a cross-sectional study. We included 200 female students from 6 governmental high schools. The participation in the study was voluntary.
Results: knowledge about sunlight as a source of vitamin D is high with 82.50%. Knowledge about vitamin D deficiency causing generalized pain is estimated with 45%.
Conclusion: proportion of vitamin D deficiency among participants was high. Despite the good knowledge that sun is the major source of vitamin D, the practice of sunlight exposure was not enough among high school students. Also the practice of supplementation was below expectation. We recommend motivation to take action regarding vitamin D status and to increase exposure time to sunlight.
Keywords: Vitamin D, deficiency, female students
Vitamin D is a steroid vitamin which promotes the intestinal absorption and metabolism of calcium and phosphorus. Under normal conditions of sunlight exposure, no dietary supplementation is necessary because sunlight promotes adequate vitamin D synthesis in the skin. Vitamin D comes from foods (egg, fish, and dairy products) and is produced in the skin; skin production of the active form of vitamin D depends on exposure to sunlight. Active people living in sunny regions produce most of the vitamin D they need from their skin. In less sunny climates, the skin production of vitamin D is markedly diminished in the winter months, especially among the elderly. In that population, vitamin D supplements become important, as are people who do not consume dietary source of vitamin D. Most infant formulas have only very low levels of vitamin D.
The American academy of pediatrics recommends vitamin D supplementation from the age of 2 months for exclusively breastfed infant. Some gastrointestinal disease and condition affect the body ability to absorb vitamin D from foods. People with kidney or liver disease may have lower level of vitamin D because these organs play vital role in creating the biologically active form of vitamin D in body. People who are obese (have BMI 30 or greater) may have lower level of vitamin D because fats cause the extraction of vitamin D from blood. A wide variety of medication includes antifungal, anti-convulsants, glucocorticoids; medication to treat AIDS/HIV can enhance the breakdown of vitamin D and lead to make it at the lower level.
Vitamin D deficiency is diagnosed by simple blood test and there is a lot of controversy about what the optimal level and deficient levels are; the test can measure 25(OH) D level. The institute of medicine sets the guidelines of serum (blood) 25(OH) D levels to be as follows:
- Deficiency:- 25(OH) D level blow 12 ng/ml.
- Inadequate:- 25(OH) D level between 12-20 ng/ml.
- Adequate:- 25(OH) D level between 20-50 ng/ml
- Excessive:- 25(OH) D level over 50 ng/ml.
Andersen conducted a study to determine the vitamin D status (serum 25-hydroxyvitamin D; S-25OHD) in a total of 199 girls living in four countries of northern Europe Denmark, Finland, Ireland and Poland in 2004. He found normal results in girls who use vitamin D supplements, and below-normal in who don’t take supplements .The study findings revealed that Vitamin D status is low in northern Europe during winter .
Harkness conduct a study to estimate the prevalence of low serum 25-hydroxyvitamin D [25(OH) D] levels in 370 adolescent girls and across racial groups and seasons. The study was conducted in northeastern United States in 2005. A significant difference was found where African-American girls’ serum 25(OH) D levels were low, and non-African-American girls’ vitamin D levels were higher; in the spring/summer months, level of vitamin D was higher compared with that obtained during the fall/winter months and weight was correlated negatively with vitamin D levels. For adolescent girls living in the northeastern United States, especially African-American girls, low 25(OH) D levels are a noteworthy concern because bone acquisition is crucial during this period of development .
A Study was done to determine the prevalence and factors associated with low concentrations of 25(OH)D in 283 healthy teenagers in northeastern United States in 2007. Francis L Weng found the fats and lean mass were not independently associated with vitamin D status in this healthy-weight sample, and Low serum 25(OH)D concentrations in healthy teenagers were related to low vitamin D intake or the cause is the difference in race or may be related to the season .
Zhang conducted a study to examine the prevalence of hypovitaminosis D and to identify whether there was any association between vitamin D status, body composition and physical exercise in 323 Chinese adolescent girls in Beijing in 2008. This showed that hypovitaminosis D was common in these subjects. In addition, body mass index, milk intake, participation in organized sports and total physical activity were all significant independent determinants of vitamin D status .
A study determining vitamin D status, bone metabolic activity and bone mass in patients with alcoholic livercirrhosis (ALC) was carried out by Dr Jack. Male patients with ALC were investigated in UK in the period 2011-2012. Deficiency in vitamin D was noted and Osteocalcin levels were low in most patients. Osteoporosis was diagnosed in patients with no correlation with disease severity and vitamin D status. Jack found Vitamin D deficiency is present in patients with ALC. Decrease in bone formation and bone mass is most probably multi causal .
Haltemen conducted a study to determine the seasonal fluctuations in serum 25-hydroxyvitamin D (25-OHD) in a group of healthy adolescents living in a northern climate in USA in the period from 2000 to 2003. The mean of serum 25-OHD of 23 participants decreased from September to March. Mean parathyroid hormone levels increased 4 pg/mL from September to March .
Salamoun conducted a study to evaluate the effect of gender, lifestyle factors and socioeconomic status on mean calcium and vitamin D intake in healthy school children and adolescents in Lebanon in 2004. He found that only a minority of students in the study met the recommendations for calcium and vitamin D. Gender, lifestyle factors, and socioeconomic status were significant predictors of calcium and vitamin D intake. Also having breakfast and physical activity affect the vitamin D level. The findings have important implications regarding the institution of dietary public health strategies to promote skeletal health in Mediterranean countries during a critical time for bone mass accrual .
Abdulbari Bener conducted a study to determine the factors associated with low concentrations of vitamin D in healthy 650 children in Qatar in the period 2007-2008. He found that vitamin D deficiency increased with age. Also family history was strongly related, and most of the vitamin D-deficient children had no physical activity and no exposure to sunlight. The study findings revealed that Qatari children are at high risk for vitamin D deficiency .
Chung carried out a study to investigate the relationship between serum vitamin D and parathyroid hormone (PTH) levels as well as to describe the prevalence and the risk factors of vitamin D deficiency (VDD) in Korean adolescents in the period 2012-2013. The Participants were 1212 adolescents aged 14 to 18. The level of 25OHD was significantly lower in overweight group than in normal weight group. The PTH levels were significantly higher in VDD group compared to vitamin D insufficiency and deficiency group. In normal weight adolescents, 25OHD and ionized calcium were independently related with PTH. VDD is very common in Korean adolescents and its prevalence increases in winter-spring season in overweight adolescents and elder age groups .
Vierucci conducted a study to estimate the prevalence of hypovitaminosis D and predictors of vitamin D status in Italian healthy adolescents. Vitamin D and PTH were evaluated in 427 Italian healthy adolescents in 2014. Enrolled adolescents had a median serum 25-OH-D level of 50.0 nmol/L, range 8.1-174.7. Vitamin D deficiency and insufficiency were detected in adolescents. Among those with deficiency, Non-white adolescents had a higher prevalence of severe vitamin D deficiency than white adolescents. Adolescents who performed <3 hours/week of outdoor exercise had higher prevalence of hypovitaminosis D .
This was an observational-descriptive cross-sectional study.
The study covered a number of females in governmental high schools in Riyadh, Saudi Arabia in the academic year 2014. It was designed to produce a representative sample of adolescents aged 16 to 18 year; accordingly, students below the target age group who have skipped some academic years to be in high school, those who were above 18, absent students, irregular or home school students, and visitor who were in the target group were excluded and were not eligible to fill in the questionnaire.
Two hundred female students from 6 governmental high schools participated in the study. The females were selected randomly from 6 high schools; one classroom was chosen from each school; the chosen classroom was given the questionnaire to be filled; random visitors or patients were given the questionnaire to be filled.
A Questionnaire with the data was collected (close indeed question) containing 3 parts:
- A question was designed to gather demographic data.
- The primary question focused on the possibility that can lead to vitamin D deficiency
- A question focused on the extant and level of knowledge about vitamin D among females.
The data gathered were clear; the information were analyzed by using SPSS program. The prevalence ratio was calculated.
|Knowlodge about vit.D||78.50%||21.40%|
|Sunlight as source||82.50%||17.50%|
|Eat dairy products||76%||24%|
|Fish and egg||44%||56%|
|linked to bones||68.50%||13.50%|
|Exposure to sun light||45%||56%|
|Knowledge about vitamin D is generally high almost in sunlight as a source 82.50%. Good practice for gaining vitamin D: having dairy products 76%, drinking milk 67.50%|
|Exposure to sunlight
|Per week||94 (47%)||106 (53%)|
|Exposure >30 minute||52 (26%)||42 (21%)|
|26% have effective sun light exposure more than 30 minutes.|
|Had vit.d deficiency in before
||Vit.d deficiency in the family
|I don’t know||68 (34%)||55 (27.5%)||0 (0%)||0 (0%)|
|No||59 (29.5%)||48 (24%)||199 (99.5%)||199 (99.5%)|
|Yes||73 (36.5%)||97 (48.5%)||1 (0.5%)||1 (0.5%)|
|48.5% have family history vitamin D deficiency, 36.5% have vitamin D deficiency in life.|
|Tenderness||37 (18.5%)||42 (21%)||79|
|Low mood||80 (40%)||52 (26%)||132|
|Generalized pain||90 (45%)||35 (17.5 %)||125|
|Restless sleep||72 (36%)||45 (22.5%)||117|
|45% of the students believe that vitamin D deficiency causes generalized pain: 40% low mood, 36% restless sleep, 18.5% tenderness.|
||GRADE 1 (79)
||GRADE 2 (54)
||GRADE 3 (67)
|Heard about vitamin||D 59 (29.5%)||45 (22.5%)||53 (26.5%)||157|
|Knowing that vitamin D linked to bone||52 (26%)||39 (19.5%)||46 (23%)||137|
|Knowing the source||38 (19%)||31 (15.5%)||37 (18.5%)||106|
|Knowing that sunlight is needed||66 (33%)||46 (23%)||53 (26.5%)||165|
|Knowing that vitamin D deficiency cause tenderness||24 (12%)||21 (10.5%)||28 (14%)||73|
|Hearing about vitamin D is higher in grade one with 29.5% than grade two with 22.5% and grade three with 26.5%.
Knowing the need to sun light is higher in grade one with 33% than grade two with 23% and grade three with 26%. There is variation in knowledge between the different grades but not significant difference.
|>5 perweek/30||3 (1.50%)||1 (0.50%)||2 (1%)|
|>5 perweek/15||4 (2%)||3 (1.5%)||3 (1.5%)|
|3-5 perweek/30||3 (1.5%)||2 (1%)||4 (2%)|
|3-5 perweek/15||5 (2.5%)||7 (3.5%)||8 (4%)|
|<3 perweek/30||7 (3.5%)||6 (3%)||5 (2.5%)|
|<3 perweek/15||11 (5.5%)||11 (4.8%)||10 (5%)|
|no exposure||58 (29%)||33 (16.5%)||49 (24.5%)|
|70% of students are not exposed to sun light, most of them (29%) from grade one.
Exposure to sunlight more than 5 times per week for 30 minutes is low in all grade but there is no significant difference.
Vitamin D deficiency is a significant problem in high school female adolescents in Riyadh city, Saudi Arabia. Students from different areas in Saudi Arabia displayed the minimal awareness of vitamin D; i.e. knowing that it was essential for musculoskeletal health and that sunlight was beneficial. On the other hand, in Riyadh high schools, students reported high awareness of vitamin D and good knowledge about the benefit of sunlight [11,12]; that is due to background and educational level of students [13-15]. Knowledge about vitamin D was almost high.
The weekly exposure to sunlight in this study was moderate and the proportion of those who had enough exposure is low. In another study performed in Saudi Arabia, the exposure to sun light was overall the same. That is due to the fact that the current study was conducted on the same geographic area with the same traditional and education .
Another study was done in Jordan on wearing hijab. The results showed low 25(OH) D levels despite exposure to sun light; whole dress impaired skin to expose to the sun light .
More than half of population don’t have enough vitamin D. In this study, the proportion of having vitamin D deficiency with family history of vitamin D deficiency was moderate. A study in UK showed slightly higher proportion than the current study. The participants in UK study had received information about Vitamin D from family or friends. Also community networks appear as a high source for the dissemination of education [18,19].
Vitamin D deficiency is common in adolescents and has implications in psychiatric and neurologic disorders. This study examined the relationship among vitamin D status, cognitive performance, mood, and physical performance in adolescents. The participants had abnormally low vitamin D levels. Vitamin D deficiency was associated with the presence of an active mood disorder, low mood and with the impairment of two of four measures of cognitive performance.
A study in America showed similar results. This is due to the lack of awareness about the importance of vitamin D in many biological processes .
Proportion of vitamin D deficiency among participants was high. Despite the good knowledge that sun is the major source of vitamin D, the practice of sunlight exposure was not enough among high school students. Also the practice of supplementation was below expectation.
- Since knowledge is not a problem, people need to be motivated to take action regarding vitamin D status.
- Increase exposure time to sun light to the average level.
- Have supplement with a vitamin D preparation.
- Conduct regular tests for vitamin D levels.
- Avoid using sunscreen during the time of exposure to sun light
We would like to thank Dr. Mona M. Hassan for her continued support.
The permission from the ethical committee of the institute was atken.
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
- Medical Intern, King Saud Medical City, King Saud University, Riyadh, Saudi Arabia
SMA and GOA participated in data acquisition, data analysis, manuscript preparation and critical revision. FIA formed the research design and assisted in data acquisition, data analysis, manuscript preparation and critical revision. GAA, SSA, AMA, AAA, NAA, MBA, ASO and ZAA took part in data acquisition, data analysis and manuscript preparation.
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