天美传媒

Vitamin D has showed great attention in the scientific and public health community, and about one billion individuals of different ages and races now being either insufficient or deficient all over the world [1-3]. The prevalence may be underestimated in elderly subjects, who may also have lower serum 25-Hydroxyvitamin D [25(OH)D] concentration [4]. Vitamin D is a fat-soluble vitamin, important to maintain extracellular calcium ion and phosphate levels that are very essential for mineral homeostasis of bone [5,6]. In addition to the role of vitamin D in skeletal health, many studies suggest that vitamin D plays important role in other health bad outcomes [2,7,8], the studies found low serum concentrations of vitamin D associated with cancer [9], diseases of immune system [10,11], diseases of cardiovascular system [12], diabetes mellitus [13-15], and weakness of muscle [16], depression [17], schizophrenia [18,19], cognitive deficits [20,21] and falls and fractures [22-25]. There is no consistent finding for vitamin D as causal in non-skeletal health [26], but it is important to maintain normal levels of vitamin D during the life of human. The production of vitamin D is from the skin through exposure to sun light. The wave length of Ultraviolet B radiation between 290 nm and 315 nm, in addition it can be taken from food and dietary supplement. By two hydroxylation, vitamin D derived from the diet or skin changes to 25- hydroxyvitamin D [25(OH)-D] in the liver, then to its active form 1,25-Dihydroxyvitamin D, in the kidney [2,27]. A lot of risk factors for low level of vitamin D in elderly have been identified, including sunscreen use, the season and time of the day, skin pigmentation, liver or kidney dysfunction, and dietary inadequacy or malabsorption, [2,27]. In addition to that, many researchers found a relationship between obesity and low vitamin D concentrations in the body [28-39], may be by the proposed action of excess body fat to sequester higher concentrations of serum 25(OH) D [31,40]. In addition to that, bioavailability of vitamin D impairment, in response to exposure to ultraviolet radiation, was observed in individuals with obesity, which is independent of the cutaneous precursor of vitamin D [31], may lead to low level of vitamin D in the serum.

Our aim in this study was to study the association between Vitamin D status and body weight (measured using Body Mass Index (BMI) in Iraqi adults.

Data from 273 Iraqi subjects came to private clinic for different clinical conditions during the period from 1^st of January through June 2018, all of them were free from chronic diseases, age between 20-50 years, all of them were married, their life style is sedentary (by history), non-smokers. Body Mass Index (BMI) measures were used to categorize subjects into under/normal weight (BMI<25 Kg/m²), overweight, and obese groups (BMI ≥ 25 Kg/m²).

VIDAS 25 OH Vitamin D TOTAL (VITD) is an automated quantitative test for use on the instruments of the VIDAS family for the determination of 25-Hydroxyvitamin D Total in human serum or plasma using the ELFA technique (Enzyme Linked Fluorescent Assay).

The VIDAS 25 OH Vitamin D TOTAL assay is to be used as an aid in the assessment of Vitamin D sufficiency.

Table 1 shows that approximately equal males and females, the age group 31-40 years is the highest number, and most of them 79.2% had body mass index more than or equal 25 and 73.3% show less than normal Vitamin D.

Table 1: Socio-demographic characteristics of participants.

Table 2 shows no significant association between vitamin D and body mass index.

Table 2: Association between vitamin D level and Body mass index.

Table 3 shows no significant association between gender and Vitamin D level.

Table 3: Association between Vitamin D level and gender.

There is a significant association between Vitamin D and age as shown in Table 4.

Table 4: Association between Vitamin D and age.

There is no one significant factor in our study population as shown in Table 5.

Table 5: Multiple logistic Regressions for different variables associated with body weight.

Approximately 73% of the participants in this study were identified as having low level of 25(OH)D concentrations in serum and this agree with a study done in Iran reported vitamin D. so it is important to supply Vitamin D to prevent the risk of falls and fractures, and late consequences of chronic comorbid conditions [41-43]. In our study there is no significant association between those who are overweight or obese (BMI ≥ 25 Kg/m²) and those who are normal weight (BMI<25 Kg/m²) and this may be attributed to the culture and religious causes which determine the type of clothes so most of the body covered and no sun exposure apart from face and hands. Many factors affect the Vitamin D level in the blood in humans. Vitamin D supplementation, and gastrointestinal, hepatic and renal diseases, diet, exposure to sunlight are some of the known factors [44-50]. Additionally, older age, winter season, black race/ethnicity, and female gender have been associated with lower 25(OH)-D levels. Weight and BMI were not significantly associated with serum 25(OH)-D concentrations [51] and this agree with our finding in this study.

Determinants of vitamin D status in morbidly obese individuals were examined, and factors considered were dietary Vitamin D intake, BMI, skin color and sun exposure. The key findings were (i) Natural skin color accounted for 13.5% of the variation in serum 25(OH)D concentrations; (ii) Serum 25(OH)-D significantly associated with age; and (iii) Serum 25(OH)D had no significant association with weight and BMI [51] There are factors, such as skin pigmentation, style of clothing, insufficient Vitamin D intake, air pollution, and lack of routine enrichment of foods with Vitamin D could be responsible for the findings of our study [52].

The study shows no association between Body mass index and level of vitamin D concentration in Iraqi population.

The author declares no conflict of interest.