25-Hydroxyvitamin D and total calcium: extraordinarily low plasma concentrations in Saudi mothers and their neonates

Relationship between vitamin D deficiency and neonatal hypocalcemia: a meta-analysis

We aimed to explore the associations of neonatal hypocalcemia with neonatal vitamin D deficiency and maternal vitamin D deficiency. A comprehensive systematic literature search using PubMed and web of science was performed for relevant articles from inception to February 17th, 2023. We used odds ratio (OR) and 95 % confidence interval (CI) as effect sizes for our meta-analysis. Publication bias was evaluated using funnel plot, Begg's test, and Egger regression test. All the statistical analyses were performed using Stata 14.0. A total of 11 studies were included and analyzed, including 452 newborns with hypocalcemia and 2,599 newborns with normal serum calcium level. Our research results revealed that vitamin D deficiency in newborns may be related to the higher prevalence of hypocalcemia (OR: 2.87, 95 % CI: 1.17-7.04). In addition, maternal vitamin D deficiency might also be a risk factor for neonatal hypocalcemia (OR: 7.83, 95 % CI: 3.62-16.92). There was a significant correlation between vitamin D deficiency and neonatal hypocalcemia.This meta-analysis indicates that newborns with vitamin D deficiency have a higher risk of hypocalcemia, and maternal vitamin D level play a crucial role in this association. Vitamin D supplementation may have a positive effect in reducing the prevalence of neonatal hypocalcemia.

Differential diagnosis of metabolic disease in a commingled sample from 19th century Hisban, Jordan

OBJECTIVE

This research attempts a differential diagnosis of skeletal lesions in a commingled sample from Hisban, Jordan, focusing on non-adults in the assemblage.

MATERIALS

2,883 well-preserved skeletal elements and 9 relatively complete skulls representing an MNI of 32 non-adults (<18 years old).

METHODS

All skeletal elements were observed macroscopically and pathophysiological processes underlying any lesions or other anomalies were assessed, followed by a comparative approach to rule out potential diagnoses.

RESULTS

The skeletal lesions observed were caused by inflammation due to chronic hemorrhaging, marrow hyperplasia due to an increase in hemopoiesis, rapid bone growth, and the impact of biomechanical strain on poorly mineralized elements. Rickets, scurvy, and acquired anemias best fit this pattern of lesions, although inflammation from other sources such as trauma or infection could not be definitively ruled out.

CONCLUSIONS

The in utero and postnatal environments at Hisban were conducive to the development of vitamin C and D deficiencies from birth until 2 years of age. The analysis of commingled remains requires an ontological shift in the importance of the individual to the population in paleopathology.

SIGNIFICANCE

This investigation demonstrates the efficacy of a combined biological and comparative approach in differential diagnosis in complicated commingled collections. In addition, it emphasizes the importance of the mother-infant dyad in understanding metabolic disease.

LIMITATIONS

Histological and radiographic analyses were not included in this diagnostic study due to COVID-19 travel restrictions.

SUGGESTIONS FOR FURTHER RESEARCH

Isotopic analysis to investigate childhood diet and histological and radiographic analyses to assess survival of deficiencies.

The relationship between serum 25-hydroxy vitamin D and blood pressure and quality of life in overweight and obese patients with type 2 diabetes mellitus compared with healthy subjects

Background:

Vitamin D is one of the known lipoprotein hormones with metabolic properties. We aimed to determine the serum 25-hydroxy vitamin D concentration in overweight/obese subjects with diabetes mellitus type Ⅱ (DM Ⅱ) in association with systolic and diastolic blood pressure and quality of life compared with healthy participants.

Methods:

The current case-control study was carried out among 80 overweight/obese subjects with DM Ⅱ, and 77 healthy subjects matched by sex, age and body mass index (BMI). Serum 25-hydroxyvitamin D concentration was measured by ELISA method. In order to examine the quality of life, the Persian version of SF36 questionnaire was used.

Results:

There was significant difference between diabetic and healthy subjects considering serum 25-hydroxyvitamin D concentration (p=0.012). Serum 25-hydroxyvitamin D concentration was inversely correlated with diastolic blood pressure (p=0.02) and positively associated with physical function (p<0.001), social function (p<0.001) and general health (p<0.001) components of quality of life in diabetic subjects and physical health sub-scale (p=0.004) in all participants.

Conclusion:

Serum 25-hydroxyvitamin D concentration was significantly lower in diabetic subjects in comparison with healthy controls. There was a significant reverse relationship between serum concentrations of 25-hydroxyvitamin D with diastolic blood pressure and on the other hand, a significant positive relationship with physical function, social function and general health components and physical health subscale of quality of life in participants with DM Ⅱ.

Significant correlation between regulatory T cells and vitamin D status in term and preterm labor

BACKGROUND AND AIM

Vitamin D insufficiency and deficiency have been associated with an increased risk of adverse pregnancy outcomes. Also, vitamin D is known to play a role in promoting the function of regulatory T-cells (Tregs). Tregs play an important role in suppressing the immune response during pregnancy. Our study aimed to investigate Tregs phenotypes in preterm and tem laboring women and its association with vitamin D level.

METHODS

This cross-sectional study included 82 pregnant women, divided into 46 term and 36 preterm laboring women in addition to 30 healthy non-pregnant women. The percentage of CD4⁺CD25⁺Foxp3⁺Treg cells and their composition of four different Treg subsets were evaluated using flow cytometric analysis. Also, serum vitamin D levels were measured by ELISA.

RESULTS

The percentage of the CD4⁺ CD25⁺ FoxP3⁺ Tregs were significantly decreased in term and preterm laboring women compared to the non-pregnant controls. The percentage of CD45RA⁺ Tregs, was significantly increased in term laboring women than preterm laboring women and non-pregnant women. Also, term labor women had increased proportion of HLA-DR^highTregs. Preterm labor women had significant increased proportion of HLA-DR^negative Tregs compared to term labor women. The overall prevalence of vitamin D deficiency and vitamin D insufficiency was higher in preterm than term laboring women and non-pregnant women. Significant positive correlations were found between serum level of 25 (OH)D and percentage of CD4⁺ CD25⁺ Foxp3⁺Tregs and percentage HLA-DR^highTregs among term and preterm laboring women with vitamin D deficiency.

CONCLUSION

There is a strong association between the percentage of Treg phenotypes and vitamin D level in term and preterm labor women with vitamin D deficiency. Also, the onset of term and preterm labor is associated with changes in the composition of the total Treg pool with different Treg subsets which in turn may be responsible for immunologic mechanisms that associated with labor induction.

High Prevalence of Vitamin D Deficiency among Iranian Population: A Systematic Review and Meta-Analysis

BACKGROUND

The prevention and correction of vitamin D deficiency requires a precise depiction of the current situation and identification of risk factors in each region. The present study attempted to determine these entities using a systematic review and meta-analysis in Iran.

METHODS

Articles published online in Persian and English between 2000 and November 1, 2016, were reviewed. This was carried out using national databases such as SID, IranMedex, Magiran, and IranDoc and international databases such as PubMed, Google Scholar, and Scopus. The heterogeneity index among the studies was determined using the Cochran (Q) and I² test. Based on the heterogeneity results, the random-effect model was applied to estimate the prevalence of vitamin D deficiency. In addition, meta-regression analysis was used to determine heterogeneity-suspected factors, and the Egger test was applied to identify publication bias.

RESULTS

The meta-analysis of 48 studies identified 18531 individuals with vitamin D deficiency. According to the random-effect model, the prevalence of vitamin D deficiency among male, female, and pregnant women was estimated to be 45.64% (95% CI: 29.63 to 61.65), 61.90% (95% CI: 48.85 to 74.96), and 60.45% (95% CI: 23.73 to 97.16), respectively. The results of the meta-regression analysis indicated that the prevalence of vitamin D deficiency was significantly different in various geographical regions (β=4.4; P=0.023).

CONCLUSION

The results obtained showed a significant prevalence of vitamin D deficiency among the Iranian population, a condition to be addressed by appropriate planning.

Roles of Vitamins D and K, Nutrition, and Lifestyle in Low-Energy Bone Fractures in Children and Young Adults

The research on skeletal system health in children and young adults, while recognizing the important role of calcium and vitamin D, goes beyond these nutritional standards. This review focuses on the role of vitamin K in combination with vitamin D and other factors in bone health. The current understanding is that maintaining bone health and prevention of low-energy fractures in any pediatric population includes nutritional factors combined with an active lifestyle. Calcium, vitamin D, and vitamin K supplementation contribute independently and collectively to bone health. The beneficial role of vitamin K, particularly vitamin K2 as menaquinone-7 (MK-7), in bone and cardiovascular health is reasonably well supported scientifically, with several preclinical, epidemiological, and clinical studies published over the last decade. Osteocalcin and matrix-Gla (glutamate-containing) protein (MGP) exemplify vitamin K-dependent proteins involved in building bone matrix and keeping calcium from accumulating in the arterial walls, respectively. An important part of the mechanism of vitamin K involves carboxylation and posttranslational activation of the family of vitamin K-dependent proteins, which prevent expression of pro-inflammatory factors and support improvement in bone mineral concentration, bone mineral density, and the quality of bone matrix. Understanding the combined approach to a healthy skeletal system in children and young adults, including the roles of vitamins D and K, calcium, healthy diet, and exercise, is particularly important in view of reports of subclinical insufficiency of vitamins D and K in otherwise healthy pediatric populations with low-energy bone fractures.

Vitamin D in Saudi Arabia: Prevalence,distribution and disease associations

More than 33 years have passed since the first paper highlighting vitamin D deficiency as a public health concern in Saudi Arabia was published in 1983. Despite "early" detection,it wasn't until the year 2010 where the interest in vitamin D research grew exponentially worldwide and was finally visible in Saudi clinical and academic areas. Since then,many landmark studies have been generated with regards to the physiologic functions of vitamin D,both skeletal and extra-skeletal. This review is limited to the prevalence,distribution A systematic review on the prevalence studies done in KSA from 2011 to 2016 was done and revealed that the prevalence of vitamin D deficiency (<50nmol/l) in Saudi Arabia among different populations (adults,children and adolescents,newborns and pregnant/lactating women) is 81.0% (Confidence Interval 95% 68.0-90.0),in line with most neighboring Gulf countries. Vitamin D deficiency in KSA has been mostly associated with bone and insulin-resistant diseases but limited data are available to prove causality. In conclusion,there is a need to develop local consensus guidelines that will identify candidates for screening,monitoring and treating those who are at most risk for vitamin D deficiency complications.

The Prevalence of Micronutrient Deficiencies and Inadequacies in the Middle East and Approaches to Interventions

Micronutrient deficiencies and inadequacies constitute a global health issue, particularly among countries in the Middle East. The objective of this review is to identify micronutrient deficits in the Middle East and to consider current and new approaches to address this problem. Based on the availability of more recent data, this review is primarily focused on countries that are in advanced nutrition transition. Prominent deficits in folate, iron, and vitamin D are noted among children/adolescents, women of childbearing age, pregnant women, and the elderly. Reports indicate that food fortification in the region is sporadic and ineffective, and the use of dietary supplements is low. Nutrition monitoring in the region is limited, and gaps in relevant information present challenges for implementing new policies and approaches to address the problem. Government-sponsored initiatives are necessary to assess current dietary intakes/patterns, support nutrition education, and to reduce food insecurity, especially among vulnerable population groups. Public-private partnerships should be considered in targeting micronutrient fortification programs and supplementation recommendations as approaches to help alleviate the burden of micronutrient deficiencies and inadequacies in the Middle East.

Extremely High Prevalence of Maternal and Neonatal Vitamin D Deficiency in the Arab Population

BACKGROUND

Vitamin D deficiency is a global public health problem. The published literature on vitamin D deficiency is limited among Arab pregnant women and its association with different metabolic markers.

OBJECTIVE

To determine the prevalence of vitamin D deficiency in Arab pregnant women and neonates and its association with various biomarker profiles.

METHODS

This is a multicenter study taken from a large prospective project in Riyadh, the capital city of Saudi Arabia. Maternal biochemical levels were measured routinely. Maternal and neonatal 25(OH)D levels were assessed using a chemiluminescence immunoassay. A total of 1,097 pregnant women >16 years old with gestational ages <24 weeks were recruited from different tertiary hospitals in Riyadh between February 2011 and June 2012.

RESULTS

Almost 85% of pregnant subjects had 25(OH)D level <50 nmol/L. Vitamin D deficiency among neonates was 88%. Maternal 25(OH)D was significantly associated with neonatal 25(OH)D (r = 0.54, p < 0.01), as well as serum calcium (r = 0.16, p = 0.02) and phosphate levels (r = 0.17, p = 0.02), and had an inverse correlation with parathyroid hormone (r = -0.22, p = 0.001).

CONCLUSION

Maternal and neonatal vitamin D deficiency is alarmingly high in Arabs and significantly associated with each another. Universal screening for serum 25(OH)D may be appropriate for Arab mothers and vitamin D supplementation mandatory until term. The study puts a spotlight on vitamin D deficiency with the hope that health professionals will address it adequately to prevent the known long-term consequences for metabolism and bone health of both mothers and their children.

Supplementation of vitamin D in pregnancy and its correlation with feto-maternal outcome

CONTEXT

Vitamin D deficiency is widely prevalent throughout the world. Pregnant women, neonates and infants form most vulnerable groups for vitamin D deficiency.

OBJECTIVE

(1) To find prevalence of vitamin D deficiency in pregnant women. (2) To evaluate the effect of supplementation with cholecalciferol in improving vitamin D levels in pregnant women and evaluate its correlation with feto-maternal outcome.

DESIGN

Randomized control trial from years 2010 to 2012.

SETTING

Tertiary care centre, Delhi, India.

PARTICIPANTS

One-hundred and eighty pregnant women. Study population divided randomly into two groups: group A: nonintervention (60 women) and group B: intervention (120 women).

INTERVENTION

The intervention group received supplementation of vitamin D in dosages depending upon 25(OH)-D levels.

MAIN OUTCOME MEASURES

Risk of maternal complications such as preterm labour, pre-eclampsia and gestational diabetes associated with vitamin D deficiency and risk of low birthweight and poor Apgar score in infants of mothers with vitamin D deficiency.

RESULTS

Adjusted serum 25(OH)-D concentration was lower in group A as compared to group B (mean 46·11 ± 74·21 nmol/l vs 80 ± 51·53 nmol/l). Forty-four percent patients in group A and 20·3% patients in group B developed preterm labour/pre-eclampsia/gestational diabetes. Newborns of mothers in group A had lower cord blood levels of 25(OH)-D levels as compared to group B (mean 43·11 ± 81·32 nmol/l vs 56·8 ± 47·52 nmol/l). They also had lower birthweight of mean 2·4 ± 0·38 kg as compared to group B 2·6 ± 0·33 kg.

CONCLUSIONS

Vitamin D supplementation reduces risk of maternal comorbidities and helps improve neonatal outcomes.

Vitamin D, the immune system and asthma

The effects of vitamin D on bone metabolism and calcium homeostasis have long been recognized. Emerging evidence has implicated vitamin D as a critical regulator of immunity, playing a role in both the innate and cell-mediated immune systems. Vitamin D deficiency has been found to be associated with several immune-mediated diseases, susceptibility to infection and cancer. Recently, there has been increasing interest in the possible link between vitamin D and asthma. Further elucidation of the role of vitamin D in lung development and immune system function may hold profound implications for the prevention and treatment of asthma.

The relationship of serum vitamin D with pre-eclampsia in the Iranian women

Vitamin D deficiency may be a risk factor for negative outcome in pregnancy, such as pre-term labour, low birthweight, intrauterine growth retardation and gestational diabetes. This study aimed to evaluate the relationship between vitamin D and pre-eclampsia. This was a case-control study of 59 pre-eclamptic women and 59 healthy pregnant women selected in two hospitals in Ahvaz, Iran. Women with term singleton pregnancy, nulliparous and of reproductive age were selected. Venous blood samples (2 mL) were taken and the level of 25-dihydroxy vitamin D (25-OH-D) was measured. If the levels of 25-OH-D were less than 10 ng mL(-1), between 10 ng mL(-1) and 29 ng mL(-1) and more than 30 ng mL(-1), they were considered as indicating deficient, insufficient and normal 25-OH-D concentrations, respectively. The independent t-test, Mann-Whitney U-test, chi-square and logistic regression were used for analysing the data. Vitamin D deficiency was significantly higher in the pre-eclampsia group [odds ratio (OR) = 24.04, confidence interval (CI) = 2.10-274.8, P = 0.01]. Older women (30-35 years) were more likely to develop pre-eclampsia compared with the control group (OR = 10.36, CI = 2.18-49.09, P = 0.003). The results showed that women with body mass index (BMI) <20 were more likely to develop pre-eclampsia. The ages between 20 years and 30 years and normal BMI were not the risk factors for pre-eclampsia. Vitamin D deficiency has a statistically significant relationship with pre-eclampsia. It seems that the serum vitamin D levels are low in Iranian women because of their particular lifestyle and they may need more than 400 IU day(-1) vitamin D supplement during pregnancy.

Maternal vitamin D status: implications for the development of infantile nutritional rickets

The mother is the major source of circulating 25-OHD concentrations in the young infant. Thus maternal vitamin D status is an important factor in determining the vitamin D status of the infant and their risk of developing vitamin D deficiency and infantile nutritional rickets. As a result, breastfed infants of mothers with vitamin D deficiency who are unsupplemented and who receive little sunlight exposure are at high risk of developing vitamin D deficiency or rickets. Despite food fortification policies in many countries and recommendations for vitamin D supplementation of at-risk groups, vitamin D deficiency and infantile rickets remain major public health challenges in many developed and developing countries. There is evidence that the current supplementation recommendations, particularly for pregnant and lactating women, are inadequate to ensure vitamin D sufficiency in these groups. A widespread and concerted effort is needed to ensure daily supplementation of breastfed and other infants at high risk with vitamin D 400 IU from birth and pregnant women in high risk communities with at least 600 IU; awareness needs to be developed among the public and medical practitioners of the urgent need to improve the vitamin D status of pregnant and lactating mothers and their infants. Further studies are required to determine the optimal doses of vitamin D supplementation in pregnancy and during lactation, and for normalizing vitamin D stores in infancy to reduce the prevalence of infantile nutritional rickets. Operational research studies also need to be conducted to understand the best methods of implementing supplementation programs and the factors that are likely to impede their success.

Updated recommendations for the diagnosis and management of osteoporosis: a local perspective

Postmenopausal osteoporosis and osteoporosis in elderly men are major health problems, with a significant medical and economic burden. Although osteopenia and osteoporosis are more common locally than in the West, fracture rates are generally less than in Western countries. Vitamin D deficiency is common in the region and contributes adversely to bone health. Vitamin D deficiency should be suspected and treated in all subjects with ostopenia or osteoporosis. The use of risk factors to determine fracture risk has been adopted by the World Health Organization and many international societies. Absolute fracture risk methodology improves the use of resources by targeting subjects at higher risk of fractures for screening and management. The King Faisal Specialist Hospital Osteoporosis Working Group recommends screening for women 65 years and older and for men 70 years and older. Younger subjects with clinical risk factors and persons with clinical evidence of osteoporosis or diseases leading to osteoporosis should also be screened. These guidelines provide recommendations for treatment for postmenopausal women and men older than 50 years presenting with osteoporotic fractures for persons having osteoporosis-after excluding secondary causes-or for persons having low bone mass and a high risk for fracture. The Working Group has suggested an algorithm to use at King Faisal Specialist Hospital that is based on the availability, cost, and level of evidence of various therapeutic modalities. Adequate calcium and vitamin D supplement are recommended for all. Weekly alendronate (in the absence of contraindications) is recommended as first-line therapy. Alternatives to alendronate are raloxifene or strontium ranelate. Second-line therapies are zoledronic acid intravenously once yearly, when oral therapy is not feasible or complicated by side effects, or teriparatide in established osteoporosis with fractures.

Hyperparathyroidism and malnutrition with severe vitamin D deficiency

BACKGROUND

Vitamin D deficiency and its associated problems are common in developing Asian countries and countries of the Middle East. Various factors, including poor nutritional status and other compounding factors such as dietary, cultural, ethnic, and environmental factors, play a major role in contributing to the poor calcium and vitamin D homeostasis. Vitamin D deficiency is thought to exacerbate signs and symptoms of hyperparathyroidism (HPT). In this overview, we present evidence of the impact of vitamin D and calcium deficiency on primary HPT (PHPT).

METHODS

We performed an evidence-based review of articles published in the English language between January 1960 and June 2008.

RESULTS

Level IV evidence suggests widespread calcium and vitamin D deficiency in developing countries (issue 1). Limited level IV evidence suggests malnutrition as a primary cause of calcium and vitamin D deficiency (issue 2). Level IV evidence suggests that calcium and vitamin deficiencies cause secondary HPT and possibly PHPT as well (issues 3 and 4). A literature search revealed only six studies that correlated vitamin D levels with clinical, biochemical, and pathologic features of PHPT (issue 5). These studies provide level IV evidence suggesting that vitamin D deficiency causes some specific clinical features of PHPT as well as exacerbating other features of the disease.

CONCLUSIONS

In the developing countries, which have severe vitamin D and calcium deficient population, PHPT patients present with advanced disease and particularly severe bone symptoms. There is presently only level IV evidence of vitamin D status affecting the clinical severity of PHPT.

Maternal vitamin D status: implications for the development of infantile nutritional rickets

The mother is the major source of circulating 25-hydroxyvitamin D concentration in the young infant. Maternal vitamin D status is an important factor in determining the vitamin D status of the infant and their risk of developing vitamin D deficiency and infantile nutritional rickets. There is evidence that the current supplementation recommendations, particularly for pregnant and lactating women, are inadequate to ensure vitamin D sufficiency in these groups. A widespread and concerted effort is needed to ensure daily supplementation of breastfed and other infants at high risk with vitamin D 400 IU from birth and of pregnant women in high-risk communities with 2000 IU. Future studies are required to determine the optimal doses of vitamin D supplementation in pregnancy and during lactation, and for normalizing vitamin D stores in infancy to reduce the prevalence of infantile nutritional rickets. Operational research studies are needed to understand the best methods of implementing supplementation programs and the factors that are likely to impede their success.

Regulatory T cells, inflammation and the allergic response-The role of glucocorticoids and Vitamin D

Regulatory T cells (TRegs) play a central role in the maintenance of peripheral tolerance. They prevent inappropriate immune responses to ubiquitous allergens in healthy individuals, and contribute to the maintenance of immune homeostasis in the airways. Both Foxp3+ and IL-10+ TReg have been implicated in these functions. Glucocorticoids represent the mainstay of treatment for asthma and other allergic conditions, and evidence that steroids influence TReg function will be reviewed. Growing bodies of epidemiological and immunological data suggest a role for endogenous Vitamin D in immune regulation. This review will discuss the role of glucocorticoids and Vitamin D, and their potential interactions in promoting tolerance in the context of allergic disease and asthma.

Nutritional rickets: still a problem for the pediatric population

Rickets is a mineralization disorder of the growing bone. Nutritional rickets is still prevalent in many parts of the developing world and is re-emerging in developed countries. Although vitamin D deficiency plays a central role in the pathogenesis of this disease, calcium deficiency and genetic factors may also cause or contribute to the development of rickets. This review will focus on the classical form of nutritional rickets, in other words, vitamin D-deficiency rickets. The epidemiology, ethiopathogenesis, risk factors, clinical picture, diagnosis, treatment and prevention of nutritional rickets are reviewed.

Vitamin D deficiency in Turkish mothers and their neonates and in women of reproductive age

OBJECTIVE

Materno-fetal vitamin D deficiency (VDD) may occur in the early neonatal period. We aimed to evaluate the vitamin D (vitD) status and risk factors for VDD in healthy newborns and their mothers, and also in fertile women.

METHODS

Serum 25 hydroxyvitamin D3 (25(OH)D), calcium (Ca), phosphorus (P) and alkaline phosphatase (ALP) levels were measured in 70 mothers (study group) and their newborns, and in umbilical cord samples. 104 nonpregnant fertile women comprised the control group. Demographic factors such as education and clothing habits of the mother, number of pregnancies and month of delivery were recorded. A serum 25(OH)D level below 11 ng/ml was accepted as severe, 11-25 ng/ml as moderate VDD, and a value over 25 ng/ml as normal.

RESULTS

Severe VDD was found in 27% of the mothers, and moderate deficiency in 54.3%. Severe VDD was detected in 64.3% of the neonates, and moderate deficiency in 32.9%. Only 18.6% of the mothers and 2.9% of the neonates had normal vitD levels. In the control group, severe VDD was observed in 26.9%, and moderate deficiency in 45.2%. Only 27.8% of the controls had normal vitD levels. In the control group, the 25(OH)D levels of the women dressed in modern clothes were significantly higher than those of the women wearing traditional clothes. This difference was not observed in the study group because 75% of these 70 mothers wore modern clothes. Mothers giving birth during the summer months and their neonates had significantly higher serum 25(OH)D levels than those of the mothers giving birth during the winter months and their neonates.

CONCLUSION

The study has shown that in Turkey VDD is an important problem in women of reproductive age, in mothers and their neonates. The 25(OH)D levels obtained from the cord may serve as a guide in the determination of the high risk groups.

Does vitamin D make the world go 'round'?

Abstract Vitamin D has emerged from obscurity, and its effects on various organ systems throughout the body down to the cellular level are being discovered. What was once thought to be a simple hormone affecting only bone and calcium metabolism has shifted. We no longer see vitamin D as a "vitamin" important only in childhood, but as a complex hormone that is involved not only in calcium homeostasis but also in the integrity of the innate immune system. Vitamin D deficiency is linked to inflammatory and long-latency diseases such as multiple sclerosis, rheumatoid arthritis, tuberculosis, diabetes, and various cancers, to name a few. In this review, we trace how we came to view vitamin D and how that view led to one of the largest epidemics of nutrient deficiency beginning in the late 20(th) century. We then discuss the needs of vitamin D in the context of the breastfeeding mother and her infant and child, why breastfed infants are particularly at risk, and what to do about it.

Pediatric vitamin D and calcium nutrition in developing countries

Over one billion humans have insufficient circulating levels of vitamin D, and dietary insufficiency of calcium is common in developing countries. Worldwide, nutritional rickets is considered to be the most common non-communicable disease of children. Rickets can be due either to primary deficiencies of vitamin D or calcium or to combined deficiencies of both elements. Vitamin D deficiency is also increasingly linked to non-skeletal complications. Even without laboratory and radiologic resources, the diagnosis of rickets is considered clinically when a child presents with limb deformities and has beaded ribs and widened wrists and ankles. Prevention is possible through increased sun exposure and dietary enhancement. Treatment of nutritional rickets involves provision of adequate vitamin D and calcium. Further research is needed to elucidate the precise epidemiology of vitamin D and calcium deficiencies in developing countries, to determine the roles of additional pathologic factors contributing to the development and morbidity of rickets, to improve affordable and feasible means of diagnosing rickets in resource-limited areas, to better target at-risk populations for preventive interventions, to identify accurate dosing and delivery of therapeutic interventions, and to evaluate the long-term consequences of vitamin D and calcium deficiencies in childhood.

Vitamin D deficiency in children and its management: review of current knowledge and recommendations

Given the recent spate of reports of vitamin D deficiency, there is a need to reexamine our understanding of natural and other sources of vitamin D, as well as mechanisms whereby vitamin D synthesis and intake can be optimized. This state-of-the-art report from the Drug and Therapeutics Committee of the Lawson Wilkins Pediatric Endocrine Society was aimed to perform this task and also reviews recommendations for sun exposure and vitamin D intake and possible caveats associated with these recommendations.

Nutritional rickets and z scores for height in the United Arab Emirates: to D or not to D?

BACKGROUND

Vitamin D deficiency is still prevalent worldwide, including the Middle East. A cohort of patients with nutritional rickets was treated with vitamin D(2) (ergocalciferol) alone. After this intervention, patients were followed to document changes in z scores for height after treatment. The secondary aim was to determine the proportion of affected children who had vitamin D deficiency or calcium deficiency.

METHODS

Z score for height was calculated as the difference between the observed value and the median value, divided by the SD of the population. Z scores were compared in patients before and after treatment.

RESULTS

The improvement in z score after treatment was 0.86 +/- 0.95. The 95% confidence interval for the mean difference was 1.32-0.40 (t = 3.95, P < 0.001). With a diagnostic cut-off for 25 hydroxyvitamin D(3) (25D) deficiency of <25 nmol/L, only half were diagnosed with severe vitamin D deficiency. The remaining patients had presumable calcium deficiency. The alkaline phosphatase (ALP) was negatively correlated to z scores, implying that higher ALP concentrations predicted severe bone disease (lower z scores). The variables 25D and age were moderately and positively correlated (Pearson's r = 0.59, 95%CI: 0.15-0.84; P = 0.01), indicating that younger infants had the lowest 25D levels.

CONCLUSION

Vitamin D alone was efficient in resolving radiological and biochemical disturbances as well as improving z scores for height in a cohort of children with nutritional rickets, which included patients with 25D deficiency as well as calcium deficiency. The results support the hypothesis of the interplay and continuum of 25D deficiency and calcium deficiency in the pathogenesis of rickets.

Maternal vitamin D deficiency, ethnicity and gestational diabetes

AIMS

Vitamin D deficiency has been linked to impaired glucose metabolism. We determined whether serum 25-hydroxyvitamin D (25OHD) is associated with glucose metabolism in pregnant women and the effect of ethnicity on this relationship.

METHODS

We analysed serum 25OHD concentrations in 307 pregnant women attending a metropolitan obstetric clinic between October 2003 and May 2005. Measurements from 264 of the women were taken at the time of glucose tolerance testing at mid-gestation, a population therefore at increased risk for gestational diabetes. Pearson correlation analysis was used to test for univariate linear relationships between the natural log of serum 25OHD (ln-25OHD) and other variables. Multiple regression analysis was used to adjust for confounding factors.

RESULTS

Mean serum 25OHD concentration was 53.8 +/- 23.9 nmol/l (sd). Ln-25OHD was negatively correlated with serum parathyroid hormone as expected (r -0.24, confidence intervals -0.35 to -0.12). Ln-25OHD was also negatively correlated with fasting plasma glucose (r-0.20, -0.31 to -0.08), fasting insulin (r -0.20, -0.31 to -0.08) and insulin resistance as calculated by homeostasis model assessment (r -0.21, -0.32 to -0.09). The association between fasting glucose and log-transformed 25OHD concentration was of borderline significance after accounting for ethnicity, age and body mass index in multivariate analyses (-0.13, -0.26 to 0.01). The odds ratio of gestational diabetes in women with 25OHD < 50 nmol/l did not reach statistical significance (1.92, 95% confidence interval 0.89-4.17).

CONCLUSIONS

Maternal 25OHD concentrations are inversely related to fasting glucose, although further studies are required to establish whether this is independent of the effects of ethnic background.

Vitamin D therapy

The fat-soluble vitamin D prohormones, ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3), are essential for the efficient intestinal absorption of calcium and phosphate and the subsequent mineralization of bone. Inadequate vitamin D leads to chronic secondary hyperparathyroidism and osteoporosis. The increasing prevalence of osteoporosis has paralleled a pandemic of vitamin D insufficiency. Based on observational and prospective trials with clinical end points, the standards for vitamin D sufficiency have been recently revised. All patients with osteopenia or osteoporosis should be monitored with a reliable assay to maintain serum 25-hydroxyvitamin D levels more than 32 ng/dL. Patients who are taking bisphosphonates and those with coexisting primary hyperparathyroidism are not exempt from taking supplemental vitamin D.

Vitamin D status in apparently healthy adults in Kashmir Valley of Indian subcontinent

BACKGROUND

The worldwide prevalence of vitamin D deficiency is reported to be high.

OBJECTIVES

To assess the vitamin D status in apparently healthy adults in Kashmir valley by measuring serum 25-hydroxyvitamin D (25 (OH) D).

METHODS

92 healthy natives (64 men and 28 non-pregnant/non-lactating women, aged 18-40 years), residing in Kashmir for at least last 5 years and not having any suggestion of systemic disease, were selected for this study. The samples were collected throughout the year in both summer and winter months. Vitamin D deficiency was defined as a serum 25 (OH) D concentration of <50 nmol/l and graded as mild (25-50 nmol/l), moderate (12.5-25 nmol/l) and severe (<12.5 nmol/l).

RESULTS

Body mass index, total energy intake, and other nutritional parameters were comparable among subjects in different groups. Overall 76 (83%) of the subjects studied had vitamin D deficiency--25%, 33%, and 25% had mild, moderate, and severe deficiency, respectively. 49 of the 64 males and all but 1 of the 28 females were vitamin D deficient. The prevalence of vitamin D deficiency ranged from 69.6% in the employed group to 100% in the household group. Vitamin D deficiency was equally prevalent in subjects from rural and urban areas. Serum calcium and phosphorus values were comparable in subjects with and without vitamin D deficiency, while daily intake and urinary excretion of calcium were significantly lower in the former. Vitamin D deficient subjects had a significantly lower mean weekly exposure to sunlight.

CONCLUSIONS

In spite of abundant sunlight, healthy individuals in Kashmir valley are vitamin D deficient, particularly women. Serum 25 (OH) D concentrations are significantly related to sun exposure.

Vitamin D status in mothers and their newborns in Iran

BACKGROUND

Adequate vitamin D concentrations during pregnancy are necessary to neonatal calcium homeostasis, bone maturation and mineralization. The aim of study is to evaluate serum vitamin D concentrations in mothers and their newborns and effect of vitamin D deficiency on pregnancy outcomes.

METHODS

552 pregnant women were recruited from Tehran University educating hospitals in the winter of 2002. Maternal and cord blood samples were taken at delivery. The serum was assayed for 25-hydroxyvitamin D3, calcium, phosphorus and parathyroid hormone.

RESULTS

The prevalence of vitamin D deficiency in maternal and cord blood samples were 66.8% and 93.3%, respectively (<35 nmol/l). There was significant correlation between maternal and cord blood serum concentrations of vitamin D. In mothers with vitamin D deficiency, cord blood vitamin D concentrations was lower than those from normal mothers (P = .001). Also, a significant direct correlation was seen between maternal vitamin D intake and weight gain during pregnancy.

CONCLUSION

Consideration to adequate calcium and vitamin D intake during pregnancy is essential. Furthermore, we think it is necessary to reconsider the recommendation for vitamin D supplementation for women during pregnancy.

High prevalence of vitamin D insufficiency in black and white pregnant women residing in the northern United States and their neonates

In utero or early-life vitamin D deficiency is associated with skeletal problems, type 1 diabetes, and schizophrenia, but the prevalence of vitamin D deficiency in U.S. pregnant women is unexplored. We sought to assess vitamin D status of pregnant women and their neonates residing in Pittsburgh by race and season. Serum 25-hydroxyvitamin D (25(OH)D) was measured at 4-21 wk gestation and predelivery in 200 white and 200 black pregnant women and in cord blood of their neonates. Over 90% of women used prenatal vitamins. Women and neonates were classified as vitamin D deficient [25(OH)D<37.5 nmol/L], insufficient [25(OH)D 37.5-80 nmol/L], or sufficient [25(OH)D>80 nmol/L]. At delivery, vitamin D deficiency and insufficiency occurred in 29.2% and 54.1% of black women and 45.6% and 46.8% black neonates, respectively. Five percent and 42.1% of white women and 9.7% and 56.4% of white neonates were vitamin D deficient and insufficient, respectively. Results were similar at <22 wk gestation. After adjustment for prepregnancy BMI and periconceptional multivitamin use, black women had a smaller mean increase in maternal 25(OH)D compared with white women from winter to summer (16.0+/-3.3 nmol/L vs. 23.2+/-3.7 nmol/L) and from spring to summer (13.2+/-3.0 nmol/L vs. 27.6+/-4.7 nmol/L) (P<0.01). These results suggest that black and white pregnant women and neonates residing in the northern US are at high risk of vitamin D insufficiency, even when mothers are compliant with prenatal vitamins. Higher-dose supplementation is needed to improve maternal and neonatal vitamin D nutriture.

Nutritional rickets: nature or nurture?

Rickets is a mineralization disorder of the growing bone. Nutritional rickets is still prevalent in many parts of the world. Although vitamin D deficiency plays a central role in the pathogenesis of this disease, calcium deficiency and genetic factors may also cause or contribute to the development of rickets. This review will focus on the classical form of nutritional rickets: vitamin D deficiency rickets. Epidemiology, ethiopathogenesis, risk factors, the current clinical picture, diagnosis, treatment and prevention of nutritional rickets will be reviewed.

Resurrection of vitamin D deficiency and rickets

The epidemic scourge of rickets in the 19th century was caused by vitamin D deficiency due to inadequate sun exposure and resulted in growth retardation, muscle weakness, skeletal deformities, hypocalcemia, tetany, and seizures. The encouragement of sensible sun exposure and the fortification of milk with vitamin D resulted in almost complete eradication of the disease. Vitamin D (where D represents D2 or D3) is biologically inert and metabolized in the liver to 25-hydroxyvitamin D [25(OH)D], the major circulating form of vitamin D that is used to determine vitamin D status. 25(OH)D is activated in the kidneys to 1,25-dihydroxyvitamin D [1,25(OH)2D], which regulates calcium, phosphorus, and bone metabolism. Vitamin D deficiency has again become an epidemic in children, and rickets has become a global health issue. In addition to vitamin D deficiency, calcium deficiency and acquired and inherited disorders of vitamin D, calcium, and phosphorus metabolism cause rickets. This review summarizes the role of vitamin D in the prevention of rickets and its importance in the overall health and welfare of infants and children.

High prevalence of vitamin D inadequacy and implications for health

During the past decade, major advances have been made in vitamin D research that transcend the simple concept that vitamin D is Important for the prevention of rickets in children and has little physiologic relevance for adults. Inadequate vitamin D, in addition to causing rickets, prevents children from attaining their genetically programmed peak bone mass, contributes to and exacerbates osteoporosis in adults, and causes the often painful bone disease osteomalacia. Adequate vitamin D is also important for proper muscle functioning, and controversial evidence suggests it may help prevent type 1 diabetes mellitus, hypertension, and many common cancers. Vitamin D inadequacy has been reported in approximately 36% of otherwise healthy young adults and up to 57% of general medicine inpatients in the United States and in even higher percentages in Europe. Recent epidemiological data document the high prevalence of vitamin D inadequacy among elderly patients and especially among patients with osteoporosis. Factors such as low sunlight exposure, age-related decreases in cutaneous synthesis, and diets low in vitamin D contribute to the high prevalence of vitamin D inadequacy. Vitamin D production from cutaneous synthesis or intake from the few vitamin D-rich or enriched foods typically occurs only intermittently. Supplemental doses of vitamin D and sensible sun exposure could prevent deficiency in most of the general population. The purposes of this article are to examine the prevalence of vitamin D inadequacy and to review the potential implications for skeletal and extraskeletal health.

High-dose vitamin D3 supplementation in a cohort of breastfeeding mothers and their infants: a 6-month follow-up pilot study

OBJECTIVE

To examine the effect of high-dose maternal vitamin D(3) (vitD) supplementation on the nutritional vitD status of breastfeeding (BF) women and their infants compared with maternal and infant controls receiving 400 and 300 IU vitD/day, respectively.

DESIGN

Fully lactating women (n = 19) were enrolled at 1-month postpartum into a randomized- control pilot trial. Each mother received one of two treatments for a 6-month study period: 0 or 6000 IU vitD(3) plus a prenatal vitamin containing 400 IU vitD(3). The infants of mothers assigned to the control group received 300 IU vitD(3)/day; those infants of mothers in the high-dose group received 0 IU (placebo). Maternal serum and milk vitD and 25(OH)D were measured at baseline then monthly; infant serum vitD and 25(OH)D were measured at baseline, and months 4 and 7. Urinary calcium/creatinine ratios were measured monthly in both mothers and infants. Dietary and BF history and outdoor activity questionnaires were completed at each visit. Changes in skin pigmentation were measured by spectrophotometry. Data were analyzed using chi-square, t-test, and analysis of variance (ANOVA) on an intent-to-treat basis.

RESULTS

High-dose (6400 IU/day) vitD(3) safely and significantly increased maternal circulating 25(OH)D and vitD from baseline compared to controls (p < 0.0028 and 0.0043, respectively). Mean milk antirachitic activity of mothers receiving 400 IU vitD/day decreased to a nadir of 45.6 at visit four and varied little during the study period (45.6-78.6 IU/L), whereas the mean activity in the 6400 IU/day group increased from 82 to 873 IU/L (p < 0.0003). There were no differences in circulating 25(OH)D levels of infants supplemented with oral vitD versus infants whose only source of vitD was breast milk.

CONCLUSION

With limited sun exposure, an intake of 400 IU/day vitamin D(3) did not sustain circulating maternal 25(OH)D levels, and thus, supplied only extremely limited amounts of vitamin D to the nursing infant via breast milk. Infant levels achieved exclusively through maternal supplementation were equivalent to levels in infants who received oral vitamin D supplementation. Thus, a maternal intake of 6400 IU/day vitamin D elevated circulating 25(OH)D in both mother and nursing infant.

The status of biochemical parameters in varying degrees of vitamin D deficiency

Vitamin D (Vit D) is an essential element for the regulation of serum calcium, phosphate, and alkaline phosphatase (Alk Ph). Because the Vit D serum level is not usually measured directly, Vit D deficiency is diagnosed indirectly by changes in serum calcium, phosphate, and Alk Ph leves. The current study assessed the status of these biochemical parameters in subjects with different degrees of Vit D deficiency. We selected 1,210 subjects, between 20 and 69 years old, randomly from the Tehran population. Subjects with diseases or medications that modified bone metabolism were excluded from the study. Serum 25(OH) D, calcium, phosphate, Alk Ph, and parathyroid hormone (PTH) levels were measured and the status of these biochemical parameters was compared in subjects with different degrees of Vit D deficiency. Vit D deficiency was diagnosed in 79.6% of the subjects. Different degrees of Vit D deficiency were classified as follows: group 1, severe; group 2, moderate; and group 3, mild. Serum PTH levels in the Vit D-deficient groups were significantly higher than that in group 4 (normal Vit D). Serum calcium and phosphate levels in groups 1 and 2 were significantly lower than those in groups 3 and 4. No significant difference was seen in serum Alk Ph in the groups with different degrees of Vit D deficiency. The sensivity for at least one biochemical variable (calcium, phosphorus, or Alk Ph) for the detection of severe, moderate, and mild Vit D deficiency was 24.2%, 13.8%, and 6%, respectively. When the serum 25(OH) D level was reduced to less than 25 nmol/l (groups 1 and 2), the effects of Vit D deficiency on calcium and phosphate levels were obvious. Therefore, the usual biochemical parameters (calcium, phosphate, Alk Ph) alone do not have sufficient sensitivity to detect mild deficiency of Vit D.

Rickets and vitamin D deficiency in children and adolescents

This article discusses the pathogenesis, epidemiology, prevention, and treatment of nutritional rickets in children, highlighting the roles of exclusive breastfeeding and low dietary calcium intakes in its pathogenesis. The worldwide nature of the problem is described. Preventive strategies are discussed, and various treatment options are provided.

High prevalence of vitamin D deficiency among pregnant women and their newborns in northern India

BACKGROUND

Vitamin D deficiency is prevalent in India, a finding that is unexpected in a tropical country with abundant sunshine. Vitamin D deficiency during pregnancy has important implications for the newborn and infant. There are few data from India about the prevalence of hypovitaminosis D in pregnancy and in the newborn.

OBJECTIVE

Our aim was to determine the prevalence of osteomalacia and hypovitaminosis D in pregnancy and in cord blood and to correlate maternal 25-hydroxyvitamin D [25(OH)D] status with sun exposure, daily calcium intake (dietary plus supplemental), and intact parathyroid hormone (PTH) concentrations.

DESIGN

Serum calcium, inorganic phosphorus, 25(OH)D, heat-labile alkaline phosphatase, and PTH were studied in 207 urban and rural pregnant subjects at term. Alkaline phosphatase and 25(OH)D were measured in the cord blood of 117 newborns.

RESULTS

Mean maternal serum 25(OH)D was 14 +/- 9.3 ng/mL, and cord blood 25(OH)D was 8.4 +/- 5.7 ng/mL. PTH rose above the normal range when 25(OH)D was <22.5 ng/mL. Eighty-four percent of women (84.3% of urban and 83.6% of rural women) had 25(OH)D values below that cutoff. Fourteen percent of the subjects had elevated alkaline phosphatase (17% of urban and 7% of rural subjects). Calcium intake was uniformly low, although higher in urban (842 +/- 459 mg/d) than in rural (549 +/- 404 mg/d) subjects (P < 0.001). Maternal serum 25(OH)D correlated positively with cord blood 25(OH)D (r = 0.79, P < 0.001) and negatively with PTH (r = -0.35, P < 0.001).

CONCLUSION

We observed a high prevalence of physiologically significant hypovitaminosis D among pregnant women and their newborns, the magnitude of which warrants public health intervention.

Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease

Most humans depend on sun exposure to satisfy their requirements for vitamin D. Solar ultraviolet B photons are absorbed by 7-dehydrocholesterol in the skin, leading to its transformation to previtamin D3, which is rapidly converted to vitamin D3. Season, latitude, time of day, skin pigmentation, aging, sunscreen use, and glass all influence the cutaneous production of vitamin D3. Once formed, vitamin D3 is metabolized in the liver to 25-hydroxyvitamin D3 and then in the kidney to its biologically active form, 1,25-dihydroxyvitamin D3. Vitamin D deficiency is an unrecognized epidemic among both children and adults in the United States. Vitamin D deficiency not only causes rickets among children but also precipitates and exacerbates osteoporosis among adults and causes the painful bone disease osteomalacia. Vitamin D deficiency has been associated with increased risks of deadly cancers, cardiovascular disease, multiple sclerosis, rheumatoid arthritis, and type 1 diabetes mellitus. Maintaining blood concentrations of 25-hydroxyvitamin D above 80 nmol/L (approximately 30 ng/mL) not only is important for maximizing intestinal calcium absorption but also may be important for providing the extrarenal 1alpha-hydroxylase that is present in most tissues to produce 1,25-dihydroxyvitamin D3. Although chronic excessive exposure to sunlight increases the risk of nonmelanoma skin cancer, the avoidance of all direct sun exposure increases the risk of vitamin D deficiency, which can have serious consequences. Monitoring serum 25-hydroxyvitamin D concentrations yearly should help reveal vitamin D deficiencies. Sensible sun exposure (usually 5-10 min of exposure of the arms and legs or the hands, arms, and face, 2 or 3 times per week) and increased dietary and supplemental vitamin D intakes are reasonable approaches to guarantee vitamin D sufficiency.

Vitamin D requirements during lactation: high-dose maternal supplementation as therapy to prevent hypovitaminosis D for both the mother and the nursing infant

Scientific data pertaining to vitamin D supplementation during lactation are scarce. The daily recommended intake for vitamin D during lactation has been arbitrarily set at 400 IU/d (10 microg/d). This recommendation is irrelevant with respect to maintaining the nutritional vitamin D status of mothers and nursing infants, especially among darkly pigmented individuals. Our objective was to examine the effect of high-dose maternal vitamin D2 supplementation on the nutritional vitamin D status of mothers and nursing infants. Fully lactating women (n = 18) were enrolled at 1 mo after birth to 1 of 2 treatment arms, ie, 1600 IU vitamin D2 and 400 IU vitamin D3 (prenatal vitamin) or 3600 IU vitamin D2 and 400 IU vitamin D3, for a 3-mo study period. High-dose (1600 or 3600 IU/d) vitamin D2 supplementation for a period of 3 mo safely increased circulating 25-hydroxyvitamin D [25(OH)D] concentrations for both groups. The antirachitic activity of milk from mothers receiving 2000 IU/d vitamin D increased by 34.2 IU/L, on average, whereas the activity in the 4000 IU/d group increased by 94.2 IU/L. Nursing infant circulating 25(OH)D2 concentrations reflected maternal intake and the amount contained in the milk. With limited sun exposure, an intake of 400 IU/d vitamin D would not sustain circulating 25(OH)D concentrations and thus would supply only limited amounts of vitamin D to nursing infants in breast milk. A maternal intake of 2000 IU/d vitamin D would elevate circulating 25(OH)D concentrations for both mothers and nursing infants, albeit with limited capacity, especially with respect to nursing infants. A maternal intake of 4000 IU/d could achieve substantial progress toward improving both maternal and neonatal nutritional vitamin D status.

Nutritional rickets: deficiency of vitamin D, calcium, or both?

Nutritional rickets remains a public health problem in many countries, despite dramatic declines in the prevalence of the condition in many developed countries since the discoveries of vitamin D and the role of ultraviolet light in prevention. The disease continues to be problematic among infants in many communities, especially among infants who are exclusively breast-fed, infants and children of dark-skinned immigrants living in temperate climates, infants and their mothers in the Middle East, and infants and children in many developing countries in the tropics and subtropics, such as Nigeria, Ethiopia, Yemen, and Bangladesh. Vitamin D deficiency remains the major cause of rickets among young infants in most countries, because breast milk is low in vitamin D and its metabolites and social and religious customs and/or climatic conditions often prevent adequate ultraviolet light exposure. In sunny countries such as Nigeria, South Africa, and Bangladesh, such factors do not apply. Studies indicated that the disease occurs among older toddlers and children and probably is attributable to low dietary calcium intakes, which are characteristic of cereal-based diets with limited variety and little access to dairy products. In such situations, calcium supplements alone result in healing of the bone disease. Studies among Asian children and African American toddlers suggested that low dietary calcium intakes result in increased catabolism of vitamin D and the development of vitamin D deficiency and rickets. Dietary calcium deficiency and vitamin D deficiency represent 2 ends of the spectrum for the pathogenesis of nutritional rickets, with a combination of the 2 in the middle.

Vitamin D deficiency and causative factors in the population of Tehran

BACKGROUND

There are multiple studies in different countries regarding the prevalence of vitamin D deficiency. These studies showed high prevalence of vitamin D deficiency in Asian countries. This study tries to elucidate the prevalence of vitamin D deficiency and its influencing factors in population of Tehran.

METHODS

1210 subjects 20-64 years old were randomly selected. 25 (OH) D serum levels were measured. Duration of exposure to sunlight, the type of clothing and level of calcium intake and BMI were quantified based on a questionnaire.

RESULTS

A high percentage of vitamin D deficiency was defined in the study population. Prevalence of severe, moderate and mild Vitamin D deficiency was 9.5%, 57.6% and 14.2% respectively. Vitamin D serum levels had no significant statistical relation with the duration of exposure to sunlight, kind of clothing and BMI. Calcium intake in the normal vitamin D group was significantly higher than the other groups (714.67 +/- 330.8 mg/day vs 503.39 +/- 303.1, 577.93 +/- 304.9,595.84 +/- 313.6). Vitamin D serum levels in young and middle aged females were significantly lower than the older group.

CONCLUSIONS

Vitamin D deficiency has a high prevalence in Tehran. In order to avoid complications of vitamin D deficiency, supplemental dietary intake seems essential.

Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis

The purpose of this review is to put into perspective the many health benefits of vitamin D and the role of vitamin D deficiency in increasing the risk of many common and serious diseases, including some common cancers, type 1 diabetes, cardiovascular disease, and osteoporosis. Numerous epidemiologic studies suggest that exposure to sunlight, which enhances the production of vitamin D(3) in the skin, is important in preventing many chronic diseases. Because very few foods naturally contain vitamin D, sunlight supplies most of our vitamin D requirement. 25-Hydroxyvitamin D [25(OH)D] is the metabolite that should be measured in the blood to determine vitamin D status. Vitamin D deficiency is prevalent in infants who are solely breastfed and who do not receive vitamin D supplementation and in adults of all ages who have increased skin pigmentation or who always wear sun protection or limit their outdoor activities. Vitamin D deficiency is often misdiagnosed as fibromyalgia. A new dietary source of vitamin D is orange juice fortified with vitamin D. Studies in both human and animal models add strength to the hypothesis that the unrecognized epidemic of vitamin D deficiency worldwide is a contributing factor of many chronic debilitating diseases. Greater awareness of the insidious consequences of vitamin D deficiency is needed. Annual measurement of serum 25(OH)D is a reasonable approach to monitoring for vitamin D deficiency. The recommended adequate intakes for vitamin D are inadequate, and, in the absence of exposure to sunlight, a minimum of 1000 IU vitamin D/d is required to maintain a healthy concentration of 25(OH)D in the blood.