Ipovitaminosi D in eta' evolutiva. Valutazione dello stato vitaminico ed analisi dei fattori di rischio di deficienza/insufficienza di vitamina D in un gruppo di bambini, adolescenti e giovani adulti.

Premessa. Recenti evidenze hanno sottolineato come uno stato vitaminico D adeguato sia importante in età pediatrica, sia per le classiche azioni che la vitamina D esercita a livello scheletrico, sia per tutta una serie di nuove azioni “extrascheletriche”. Diversi studi riportano un’elevata prevalenza di ipovitaminosi D in molti paesi; in particolare, sono noti diversi fattori di rischio capaci di influenzare negativamente lo stato vitaminico del bambino e dell’adolescente. I principali fattori di rischio modificabili sono la scarsa esposizione solare, l’obesità e la mancata profilassi con vitamina D. Ad oggi, pochi studi hanno analizzato la prevalenza dell’ipovitaminosi D in età evolutiva in Italia e il ruolo dei diversi fattori di rischio nell’influenzare lo stato vitaminico D dei bambini, degli adolescenti e dei giovani adulti italiani. Scopi dello studio. Valutazione dello stato vitaminico D e del metabolismo fosfo-calcico in un gruppo di bambini, adolescenti e giovani adulti residenti nell’area pisana. Valutazione della prevalenza di deficienza/insufficienza di vitamina D in età evolutiva. Analisi dei principali fattori di rischio di sviluppare ipovitaminosi D in età evolutiva. Pazienti. Nel presente studio sono stati esaminati 652 pazienti, reclutati nel periodo compreso tra Ottobre 2010 e Dicembre 2012 presso la Sezione di Endocrinologia Pediatrica e il Reparto di Degenza della Pediatria di Pisa. I pazienti analizzati sono stati suddivisi nelle seguenti classi di età: bambini (n = 283, età compresa tra 2.0-10.9 anni), adolescenti (n = 248, età compresa tra 11.0-17.9 anni), giovani adulti (n = 121, età compresa tra 18.0-21.0 anni). Al momento della valutazione, nessun paziente aveva ricevuto supplementazione con vitamina D nei 12 mesi precedenti. Metodi. Il protocollo di studio ha previsto la valutazione, mediante prelievo venoso, dei livelli di 25-idrossivitamina D (25-OH-D), 1,25-diidrossivitamina D [1,25(OH)2D], paratormone (PTH), calcio e fosforo. Lo stato vitaminico D è stato valutato in base ai livelli circolanti di 25-OH-D, secondo i cut off di riferimento proposti dall’Endocrine Society (deficienza per valori di 25-OH-D < 20 ng/ml, insufficienza per valori di 25-OH-D compresi tra 20 e 30 ng/ml, ipovitaminosi per valori di 25-OH-D inferiori a 30 ng/ml, sufficienza per 25-OH-D ≥ 30 ng/ml). La valutazione dei diversi fattori di rischio di sviluppare ipovitaminosi D è stata effettuata mediante la somministrazione di un questionario. I dati sulle abitudini alimentari raccolti sono stati elaborati per mezzo di un software specifico per l’analisi alimentare (questionari completi 342/652, 52.4%). Risultati. Dall’analisi del campione intero è emersa un’elevata prevalenza di ipovitaminosi D (79.4%), con percentuali di deficienza e di insufficienza rispettivamente del 45.7% e del 33.7%. I livelli medi circolanti di 25-OH-D sono risultati 22.6 ± 11.0 ng/ml. Gli adolescenti presentavano livelli medi di 25-OH-D inferiori ai bambini e ai giovani adulti (rispettivamente 21.3 ± 10.2 ng/ml, 23.9 ± 11.5 ng/ml, 22.5 ± 11.1 ng/ml, p=0.030). La stagione di esecuzione del prelievo influenzava lo stato vitaminico D, con livelli di 25-OH-D massimi in estate e minimi in primavera (28.8 ± 13.0 ng/ml vs 19.6 ± 8.7 ng/ml, p 30 giorni (91.8%, 79.6%, 80.9%, p=0.001). L’applicazione regolare di filtri solari determinava, nei soggetti esposti al sole > 30 giorni, livelli inferiori di 25-OH-D rispetto ai soggetti che non utilizzavano o facevano uso occasionale dei filtri (20.2 ± 7.5 ng/ml vs 23.6 ± 9.3 ng/ml, p=0.019). Il sesso e la residenza non influenzavano lo stato vitaminico D. Mediante regressione logistica, i fattori di rischio di ipovitaminosi D sono risultati la stagione del prelievo (autunno OR 5.72, inverno OR 15.32, primavera OR 16.57 vs estate), lo stato ponderale (sovrappeso OR 6.51, obesità OR 4.61 vs normopeso), l’esposizione solare ( 15 giorni), l’utilizzo regolare di filtri solari (OR 2.35 vs no-occasionale). I livelli di 25-OH-D correlavano inversamente con i valori di PTH (R2=0.12, p 65 pg/ml). Di questi, 36 (82%) presentavano livelli di 25-OH-D nel range della deficienza, mentre 8 (18%) presentavano una condizione di iperparatiroidismo secondario già nel range dell’insufficienza di vitamina D. Per quanto riguarda l’analisi dei livelli di calcio, fosforo e 1,25(OH)2D in base allo stato vitaminico, ad eccezione dei bambini in cui i livelli di calcio risultavano significativamente superiori nei soggetti con stato vitaminico sufficiente, negli adolescenti e nei giovani adulti non emergevano differenze significative. Dall’analisi alimentare emergeva che i bambini presentavano apporti medi giornalieri di calcio inferiori rispetto ad adolescenti e giovani adulti (rispettivamente 508.9 ± 177.9, 549.8 ± 206.6, 817.4 ± 463.5 mg/die, p<0.0001). Gli apporti giornalieri medi di vitamina D con la dieta risultavano trascurabili in tutti i gruppi di età . Conclusioni. I pazienti in età evolutiva (2-21 anni) residenti nell’area pisana non sottoposti a profilassi con vitamina D presentano un’elevata prevalenza di ipovitaminosi D, in particolare durante l’adolescenza. L’ipovitaminosi D può ripercuotersi negativamente sulla salute ossea del bambino e dell’adolescente, in quanto può portare all’instaurarsi di iperparatiroidismo secondario. Dato il riscontro di casi di iperpara-tiroidismo anche nella fascia dell’insufficienza di vitamina D, si consiglia di considerare livelli di 25-OH-D > 30 ng/ml come espressione di uno stato vitaminico D ottimale. Alla latitudine di Pisa, i fattori che maggiormente influenzano lo stato vitaminico D sono le stagioni dell’anno (inverno-primavera), l’etnia non caucasica, la scarsa esposizione solare durante l’estate, l’utilizzo regolare di filtri solari e l’eccesso ponderale. L’apporto dietetico di vitamina D è risultato trascurabile, confermando come l’esposizione alla luce solare rappresenti la forma principale di approvvigionamento di vitamina D. Nei soggetti in cui sono presenti uno o più fattori di rischio di ipovitaminosi D appare opportuno promuovere un’adeguata profilassi con vitamina D

Vitamin D status and predictors of hypovitaminosis D in internationally adopted children

To evaluate vitamin D status in internationally adopted children at first medical evaluation in Italy and to identify possible risk factors for hypovitaminosis D in this population.25-hydroxyvitamin D [25(OH)D] levels were analyzed in internationally adopted children consecutively recruited at one Italian Center between 2010 and 2014 as part of the first screening protocol. Demographic, clinical and laboratory data were prospectively collected. Serum 25(OH)D levels <10 ng/mL, <20 ng/mL, and <30 ng/mL were used to define severe vitamin D deficiency, vitamin D deficiency and hypovitaminosis D, respectively.962 internationally adopted children (median age: 5.47 years; IQR:3.14-7.93) were included in the study. Median 25(OH)D level was 22.0 ng/mL (IQR:15.0-30.0 ng/mL); 710/962 (73.8%) children showed hypovitaminosis D (<30 ng/mL), 388/962 (40.3%) had vitamin D deficiency (<20 ng/dL), and 92/962 (9.6%) had severe vitamin D deficiency (<10ng/mL). No case of clinical rickets was observed. Hypovitaminosis D was particularly frequent (>90%) in children adopted from Ethiopia, Peru, India, Bulgaria and Lithuania. At multivariate analysis an increased risk of hypovitaminosis D was found to be associated with: age ≥ 6 years, time spent in Italy ≥ 3 months, blood sample taken in winter, spring or fall, compared to summer. Gender, ethnicity/continent of origin, tubercular infection, intestinal parassitosis and BMI-z-score < -2 were not associated with vitamin D status.Hypovitaminosis D is common in internationally adopted children, from all ethnic group. The evaluation of serum 25(OH)D level could be useful early after the adoption to promptly start vitamin D supplementation/treatment if needed

Prevalence of hypovitaminosis D and predictors of vitamin D status in Italian healthy adolescents

Background: Vitamin D plays an important role in health promotion during adolescence. Vitamin D deficiency and insufficiency are common in adolescents worldwide. Few data on vitamin D status and risk factors for hypovitaminosis D in Italian adolescents are currently available. Methods. 25-hydroxyvitamin D (25-OH-D) and parathyroid hormone (PTH) levels were evaluated in 427 Italian healthy adolescents (10.0-21.0 years). We used the following cut-off of 25-OH-D to define vitamin D status: deficiency < 50 nmol/L; insufficiency 50-75 nmol/L; sufficiency ≥ 75 nmol/L. Hypovitaminosis D was defined as 25-OH-D levels < 75.0 nmol/L and severe vitamin D deficiency as 25-OH-D levels < 25.0 nmol/L. We evaluated gender, residence, season of blood withdrawal, ethnicity, weight status, sun exposure, use of sunscreens, outdoor physical activity, and history of fractures as predictors of vitamin D status. Results: Enrolled adolescents had a median serum 25-OH-D level of 50.0 nmol/L, range 8.1-174.7, with 82.2% having hypovitaminosis D. Vitamin D deficiency and insufficiency were detected in 49.9% and 32.3% of adolescents, respectively. Among those with deficiency, 38 subjects were severely deficient (38/427, 8.9% of the entire sample). Non-white adolescents had a higher prevalence of severe vitamin D deficiency than white subjects (6/17-35.3% vs 32/410-7.8% respectively, p = 0.002). Logistic regression showed increased risk of hypovitaminosis D as follows: blood withdrawal taken in winter-spring (Odds ratio (OR) 5.64) compared to summer-fall period; overweight-obese adolescents (OR 3.89) compared to subjects with normal body mass index (BMI); low sun exposure (OR 5.94) compared to moderate-good exposure and regular use of sunscreens (OR 5.89) compared to non regular use. Adolescents who performed < 3 hours/week of outdoor exercise had higher prevalence of hypovitaminosis D. Gender, residence, and history of fractures were not associated with vitamin D status. Serum 25-OH-D levels were inversely related to PTH (r = -0.387, p < 0.0001) and BMI-SDS (r = -0.141, p = 0.007). 44/427 (10.3%) adolescents showed secondary hyperparathyroidism. Conclusions: Italian adolescents have high prevalence of vitamin D deficiency and insufficiency. Pediatricians should tackle predictors of vitamin D status, favoring a healthier lifestyle and promoting supplementation in the groups at higher risk of hypovitaminosis D. © 2014 Vierucci et al.; licensee BioMed Central Ltd

Skin advanced glycation end-products evaluation in infants according to the type of feeding and mother’s smoking habits

Objectives: This study was conducted to assess whether formula-fed infants had increased skin advanced glycation end-products compared with breastfed ones. We also evaluated the effect of maternal smoke during pregnancy and lactation on infant skin advanced glycation end-products accumulation. Methods: Advanced glycation end-product–linked skin autofluorescence was measured in 101 infants. Results: In infants born from non-smoking mothers, advanced glycation end-products were higher in formula-fed subjects than in breastfed subjects (0.80 (0.65–0.90) vs 1.00 (0.85–1.05), p < 0.001). Advanced glycation end-products in breastfed infants from smoking mothers were higher than in those from non-smoking mothers (0.80 (0.65–0.90) vs 1.00 (0.90–1.17), p = 0.009). Conclusion: Formula-fed infants had increased amounts of advanced glycation end-products compared with the breastfed ones, confirming that breast milk represents the best food for infants. Breastfed infants from mothers smoking during pregnancy and lactation had increased skin advanced glycation end-products, suggesting that smoke-related advanced glycation end-products transfer throughout breast milk. Moreover, advanced glycation end-products may already increase during gestation, possibly affecting fetal development. Thus, we reinforced that smoking must be stopped during pregnancy and lactation

Vitamin D status in internationally adopted children divided for country of origin.

<p>Vitamin D status in internationally adopted children divided for country of origin.</p

Characteristics of the 962 internationally adopted children included in the study.

<p>Characteristics of the 962 internationally adopted children included in the study.</p

Serum 25(OH)D levels [median (IQR)] and vitamin D status related to presumed risk factors for hypovitaminosis D.

<p>Serum 25(OH)D levels [median (IQR)] and vitamin D status related to presumed risk factors for hypovitaminosis D.</p

Gestational Vitamin D3 Supplementation and Sun Exposure Significantly Influence Cord Blood Vitamin D Status and 3-Epi-25-Hydroxyvitamin D3 Levels in Term Newborns

Background and aims. High prevalence of hypovitaminosis D is worldwide reported among pregnant women and newborns. We assessed cord blood 25-hydroxyvitamin D3 [25(OH)D3] and 3-epi-25-hydroxyvitamin D3 (C3-epimer) levels in relation to assumed maternal risk factors for hypovitaminosis D.Methods. We enrolled 246 term newborns during summer. 175/246 mothers were supplemented with a daily variable dosage (200-1,000 IU) of vitamin D3 during pregnancy. Cord blood 25(OH)D3 and C3-epimer concentrations were analyzed by high performance liquid chromatography tandem mass spectrometry. Results. Median cord blood 25(OH)D3 levels were 23.4 ng/mL (16.9-28.8). The prevalences of vitamin D sufficiency (≥30.0 ng/mL), insufficiency (20.0-29.9 ng/mL), and deficiency (&lt;20.0 ng/mL) were 19.9%, 45.9%, and 34.2%, respectively. Non-Caucasian ethnicity, housewife life, weight excess, negligible sun exposure and absent gestational vitamin D supplementation were associated with both reduced cord blood 25(OH)D3 and C3-epimer levels. C3-epimer/25(OH)D3 ratio was 15.1% (13.6%-18.4%) and it was not related to any of the assumed risk factors for hypovitaminosis D. Conclusions. Cord blood vitamin D deficiency was common, particularly in newborns from mother not receiving vitamin D supplementation and with poor sun exposure. C3-epimer levels were high in cord blood, causing possible misclassification of vitamin D status if they were not distinguished from 25(OH)D3 concentration

Vitamin D in childhood and adolescence:an expert position statement

Vitamin D is a key hormone in the regulation of calcium and phosphorus metabolism and plays a pivotal role in bone health, particularly during pediatric age when nutritional rickets and impaired bone mass acquisition may occur. Great interest has been placed in recent years on vitamin D’s extraskeletal actions. However, while recent data suggest a possible role of vitamin D in the pathogenesis of several pathological conditions, including infectious and autoimmune diseases, the actual impact of vitamin D status on the global health of children and adolescents, other than bone, remains a subject of debate. In the meantime, pediatricians still need to evaluate the determinants of vitamin D status and consider vitamin D supplementation in children and adolescents at risk of deficiency. This review is the result of an expert meeting that was held during the congress “Update on vitamin D and bone disease in childhood” convened in Pisa, Italy, in May 2013. Conclusion: The collaboration of the international group of experts produced this “state of the art” review on vitamin D in childhood and adolescence. After dealing with vitamin D status and its determinants, the review outlines the current debate on vitamin D’s health benefits, concluding with a practical approach to vitamin D supplementation during childhood and adolescence