Vitamin D requirements in adolescents: what is the target?

A randomized clinical trial comparing 3 different replacement regimens of vitamin D in clinically asymptomatic pediatrics and adolescents with vitamin D insufficiency

BACKGROUND

Pediatric and Adolescent populations both have special needs for vitamin D especially for growing bone. Inadequate vitamin D is defined as 25 (OH) D(25hydroxy vitamin D) < 30 ng/ml.

METHODS

We conducted a randomized, controlled clinical trial from July 2014 over 1 year, aiming to assess the changes in 25 (OH) D and biochemical outcome on calcium and PTH(parathyroid hormone) using 3 different regimens of vitamin D replacement. Initial and 4 month 25 (OH) D, calcium, PTH and 12 month 25 (OH) D levels were assayed. Participants divided into 3 groups: 1) given 400 IU daily, 2) given 45000 IU weekly for 2 months then 400 IU daily, 3) given 2000 IU daily for 3 months then 1000 IU daily.

RESULTS

The results showed significant difference between the 3 groups as regards 25 (OH) D at 4 and 12 months (P < 0.001). Regimens used in group 2 and 3 caused increase in 25 (OH) D after 4 month (median increase is 225% and 200% respectively). 25 (OH) D dropped in group 1 and 2 (median decrease is 42 and 53% respectively) but continued to increase in group 3 (median change is 6%). In group 2 serum calcium median change was 1.2% with few cases of hypercalcuria. 94.9, 76.1 and 7.7 are the percent of vitamin D deficient participants in groups 1, 2 and 3 respectively after 12 months follow up.

CONCLUSION

We advise as a replacement for vitamin D insufficiency, low loading dose with high maintaince dose rather than the opposite to achieve steady increase in serum 25 (OH) D with no hypercalcemic side effects.

Hypovitaminosis D in adolescent females--an analytical cohort study in the United Arab Emirates

BACKGROUND

Despite living in a sunny country, hypovitaminosis D is common in women of reproductive age in Al Ain, United Arab Emirates (UAE).

AIMS AND OBJECTIVES

To establish the prevalence of hypovitaminosis D in adolescent female Emirati nationals and its risk factors.

METHODS

This was an analytical prospective cohort study of 350 female Emirati nationals aged 11-18 years attending public schools in Al Ain. Socio-economic status, diet and amount of sun exposure were evaluated by face-to-face interviews. Serum total 25 (OH) vitamin D (D2 + D3) levels were measured by electrochemiluminescence assay. The prevalence of hypovitaminosis D was calculated and the association with risk factors analysed.

RESULTS

Data were complete for 293 girls. Only one girl [prevalence 0.3%, 95% confidence interval (CI) 0.01-1.9] had vitamin D sufficiency (serum vitamin D levels >75 nmol/L). Three girls (1.0%, 95% CI 0.2-2.9) had vitamin D insufficiency (50-75 nmol/L), 58 (19.8%, 95% CI 15.0-25.5) were deficient (27.5-50 nmol/L) and 231 (78.8%, 95% CI 68.9-89.6) had severe deficiency (<27.5 nmol/L). Serum vitamin D levels declined between the ages of 11 and 13 years before progressively rising until the age of 18 years but without regaining the levels they were at the age of 11. There was no statistically significant difference between the vitamin D status groups in age, body mass index, accommodation type, family income, percentage of surface area unexposed to the sun when outdoors, consumption of oily fish or total vitamin D intake.

CONCLUSION

The finding of a high prevalence of hypovitaminosis D in adolescent females in UAE is of serious concern for their health and that of their infants during their reproductive lives. Adolescent girls with a similar social and cultural background currently living in less sunny, industrialised countries might also be at risk.

Vitamin D status and associated factors of deficiency among Jordanian children of preschool age

BACKGROUND/OBJECTIVES

Vitamin D deficiency in children remains a global concern. Although literature exists on the vitamin D status and its risk factors among children in the Middle East, findings have yielded mixed results, and large, representative community studies are lacking.

SUBJECTS/METHODS

In a nationally representative survey of 1077 Jordanian children of preschool age (12-59 months) in Spring 2010, we measured 25(OH)D3 concentrations by liquid chromatography-tandem mass spectrometry and calculated prevalence ratios for deficiency associated with various factors.

RESULTS

RESULTS showed 19.8% (95% confidence interval (CI): 16.4-23.3%) deficiency (<12 ng/ml) and 56.5% (95% CI: 52.0-61.0%) insufficiency (<20 ng/ml). In adjusted models, prevalence of deficiency was higher for females compared with males (prevalence ratio (PR)=1.74, 95% CI: 1.22-2.47, P=0.002) and lower for children 24-35 months of age (PR=0.64, 95% CI: 0.44-0.92, P=0.018) compared with children 12-23 months of age. In rural areas, there was no difference in prevalence of vitamin D deficiency between those whose mothers had/did not have vitamin D deficiency (P=0.312); however, in urban areas, prevalence of vitamin D deficiency was 3.18 times greater among those whose mothers were vitamin D deficient compared with those whose mothers were not deficient (P=0.000).

CONCLUSIONS

Vitamin D deficiency and insufficiency pose significant public health problems in Jordanian children with female children disproportionately affected. Strong associations between vitamin D status in children and urban residency and maternal vitamin D status suggest that the behaviors related to sun exposure in urban mothers likely also affect the sun exposure and thus vitamin D status of their children.

Prevalence of vitamin d deficiency in a pediatric hospital of eastern India

Vitamin D deficiency is highly prevalent in Indian children of northern, western and southern states. Serum 25 hydroxy cholecalferol (ng/ml) was analyzed in 310 children and adolescents of pediatric hospital of Kolkata, India. Serum calcium (mg/dl), phosphorous (mg/dl) and alkaline phosphatase (IU/L) data was obtained. Median 25(OH)D was 19 ng/ml. 19.2 % of population had serum 25(OH)D < 10 ng/ml (severe deficiency), 52.9 % had <20 ng/ml (deficiency), 24.5 % had 20-29 ng/ml (insufficiency) and 22.6 % had >30 ng/ml (optimum). Deficiency was highest in adolescents (86.1 %), followed by school children (61.0 %), lowest in pre-school children (41.6 %). 25(OH)D concentrations was lowest in winters (P = 0.002) and spring (P = 0.03) compared to summer. There was no correlation with calcium (P = 0.99), phosphorous (P = 0.23) and ALP (P = 0.63). There is high prevalence of vitamin D deficiency in children and adolescents of eastern India. Prevalence was lower in younger subjects. 25(OH)D did not correlate with bone mineral markers.

Vitamin D intake and serum vitamin D in ethnically diverse urban schoolchildren

OBJECTIVE

Low serum vitamin D, which largely affects ethnic minorities, is associated with obesity and other chronic diseases. Little is known about racial/ethnic differences in intake, particularly in children, or if any differences are associated with differences in serum 25-hydroxyvitamin D (25(OH)D). The objective of the present study was to determine whether racial/ethnic differences in dietary vitamin D intake exist and whether they explain differences in 25(OH)D.

DESIGN

Vitamin D intakes (Block Kids 2004 FFQ) and 25(OH)D were measured. Race/ethnicity was parent-reported (white (37·9 %), Hispanic (32·4 %), black (8·3 %), Asian (10·3 %), multi-racial/other (11·0 %)). Multivariable analyses were conducted to examine the associations among dietary vitamin D and race/ethnicity, as well as 25(OH)D, independent of BMI Z-score and other covariates.

SETTING

Elementary/middle schools in Somerville, MA, USA, during January-April 2010.

SUBJECTS

Schoolchildren (n 145) in 4th-8th grade.

RESULTS

Only 2·1 % met the 2011 RDA (15 μg/d (600 IU/d)). Average dietary intake was 3.5 (sd 2.2) μg/d (140 (sd 89·0) IU/d). No racial/ethnic differences in intake were evident. Most (83·4 %) were 25(OH)D deficient (<20 ng/ml; 16·0 (sd 6·5) ng/ml). In ANOVA post hoc analyses, 25(OH)D levels were lower in Hispanics than whites (14·6 (sd 6·1) ng/ml v. 17·9 (sd 4·6) ng/ml; P < 0·01). Dietary vitamin D was associated with 25(OH)D overall (P < 0·05), but did not explain the racial/ethnic differences in 25(OH)D.

CONCLUSIONS

Most children in this north-east US sample did not meet dietary recommendations for vitamin D and were vitamin D deficient. Dietary vitamin D did not explain the difference in 25(OH)D between Hispanic and white children. Further research is needed to determine if changes in dietary vitamin D by race/ethnicity can impact 25(OH)D levels.

Insights into bone health in Duchenne muscular dystrophy

Poor bone health is a significant problem for patients with Duchenne muscular dystrophy (DMD), a progressive, disabling disease. Although the primary focus of DMD disease pathogenesis is degeneration of striated muscle, impairment of bone health likely has a role in the disease that has only been superficially examined to date. Deficiency of bone mineral density and increased incidence of bone fractures are well-recognized clinical components of the DMD phenotype. Furthermore, therapy with corticosteroids, an approved treatment for DMD that prolongs ambulation, may have multiple effects on bone health in DMD patients. This review examines the evidence in preclinical models and in human DMD disease that provides insight into the role performed by bone in the disease pathogenesis and phenotype of DMD. The information reviewed here points toward the need for mechanistic and therapeutic studies to optimize bone health in DMD patients.