Vitamin D status in healthy Romanian caregivers and risk of respiratory infections

Abstract

Conclusions: Vitamin D status is alarmingly poor in active, relatively young women residing in Romania. If our results are reproduced by other investigations, action to improve vitamin D status at the population level is necessary. We were not able to show a statistically significant relationship between vitamin D status and infection risk in our material. Keywords Vitamin D Romania Infections riskThe important role of vitamin D in Ca metabolism and bone health is well accepted (1) . The discovery that most human tissues are able to produce and use active vitamin D triggered extensive research of vitamin D's biological functions beyond bone health. Experimental and epidemiological work has shown that vitamin D reduces risk and improves prognosis of cancer (2) . Moreover, vitamin D plays important roles in the regulation of innate and adaptive immunity and seems to decrease the risk and modulate the course of various infections (3)(4)(5)(6) . Vitamin D itself has low biological activity, but undergoes activation by successive hydroxylations: in the liver with the formation of 25-hydroxyvitamin D (25(OH)D) and in the kidney with the production of 1,25-dihydroxyvitamin D (1,25(OH) 2 D) (7) . It is becoming increasingly clear that 1,25(OH) 2 D also can be produced outside the kidney. This local production may have very important implications for the effects of vitamin D on health.The body is able to synthesize vitamin D upon sufficient UV exposure. In fact, skin synthesis is the main source of vitamin D in most populations, proving a high efficiency of this reaction when the oral intake (from regular poor diet) is low (8) . It is believed that a whole-body exposure at one MED (minimal erythema dose) generates 250-500 mg (10 000-20 000 IU) of vitamin D, which is equivalent to the vitamin D content of 250 ml of cod-liver oil (9)(10)(11) .Since man is to a high degree dependent on the skin production of vitamin D, factors altering either the fluence rate of UV radiation (like altitude, latitude, cloud cover, clothing habits, use of sun screens) or skin properties (like skin colour, age) are the main predictors of vitamin D status.Romania is located at a latitude of 458N which ensures a sufficient UV fluence rate to efficiently produce vitamin D from March to October (12) . At the same time, Romanians have no practice of vitamin D food fortification or tradition of cod-liver oil consumption. This means that their

The Value of Osteopontin in the Assessment of Bone Mineral Density Status in Postmenopausal Women

“…The poor vitamin D status was found recently also in young women residing in Romania. 37 More extensive studies on vitamin D status in the Romanian population are required owing to the possibility that the poor vitamin D status could be a problem in the national health.…”

Immunoregulatory mechanisms of vitamin D relevant to respiratory health and asthma

“…Wayse et al 134 Laaksi et al 135 Ginde et al 136 Roth et al 137 Jartti et al 138 Sabetta et al 139 Freishtat et al 119 Berry et al 140 Camargo et al 31 Morales et al 124 Hirani et al 141 Science et al 142 Aregbesola et al 143 Gale et al 45 McNally et al 144 Porojnicu et al 145 patients, 17,53 suggesting that compensatory mechanisms exist to counter any effects of vitamin D enhancement of T H 2 responses. For example, increased IgE-mediated sensitization to common allergens, such as peanut, ragweed, and oak, has been observed in vitamin D-deficient children.…”

Low Serum 25-Hydroxyvitamin D Level and Risk of Upper Respiratory Tract Infection in Children and Adolescents

“…Several observational studies have evaluated the role of serum 25-hydroxyvitamin D (25(OH)D) concentration in respiratory tract infections [16][17][18][19][20][21][22][23][24][25]. However, all these studies have important limitations including short follow-up period [16], small sample size [16-20, 24, 25], case-control design [18][19][20], or crosssectional design with retrospective ascertainment of symptoms [21,22] and failure to obtain laboratory confirmation of self-reported illness [16,[21][22][23]. The studies in adults have shown an association between lower vitamin D levels and increased respiratory infections (self-reported) [21,22,24] and absence from work due to respiratory symptoms [23].…”