Epidemiology of vitamin D deficiency in children presenting to a paediatric outpatient service in the UK J M Reed, J H Davies, L Blake, A Jackson, N M P Clarke Southampton General Hospital & University of Southampton

Background Vitamin D3 (cholecalciferol) is obtained from 2 sources: Sunlight exposure (UV-B rays) Dietary intake: oily fish products, fortified products and supplements.

Formation of cholecalciferol 7-dehydrocholesterol

Background

Definitions Davies et al, Arch Dis Child 2010; Cheetham et al, BMJ 2010; Misra et al Pediatrics 2008

Prevalence of vitamin D deficiency in developed countries, adults vs Prevalence of vitamin D deficiency in developed countries, adults vs. children Hypponen et al, Am J Clin Nutr, 2007 n=7347, age 45 y, UK, all white, winter/ spring 25-OHD measurement 87.1% < 75 nmol/l 46.6% < 40 nmol/l 15.5% < 25 nmol/l Ford et al, Ann Clin Biochem, 2006 n=830, UK adults, multicultural inner city, Sept 25-OHD measurement < 25 nmol/l: 1 in 8 White 1 in 4 Black Afro-Caribbean 1 in 3 Asians Kumar et al, Pediatrics, 2009 n=6275, USA, age 1-21 y, NHANES 2001-2004, 25-OHD measurement 61%, 37.5-72.5 nmol/l 9%, < 37.5 nmol/l association with cardiovascular risk factors what is the prevalence of vitamin D deficiency in UK children?

Mode of presentation of symptomatic vitamin D deficiency in the UK 16 infants (6 Asian, 10 Black) from UK all breast fed 6 cardiac arrest 3 died 8 ventilated 2 required by-pass 12 required IV support 2 referred for cardiac transplant Heart 2006

Recent trends & clinical features of vitamin D deficiency presenting to a children’s hospital in Glasgow Ahmed et al, Arch Dis Child, 2010

Methods Prospective study to investigate the prevalence of deficiency in our patient population Vitamin D level in known bone pathologies - or Requested as part of investigative work-up for unexplained bone pain

Stages of Tibia Vara 1 2 3 4 5 6

Changing incidence of slipped capital femoral epiphysis: A relationship with obesity JBJS Br. 2008; 90: 92-4

31.1.10 2.6.10

Vitamin D deficiency in children presenting to the paediatric orthopaedic clinic, Southampton (1) 25-OHD measured in those with bone pain or deformity 187 children from 2008 – 2010 75 deficient (60 insufficiency, 15 severe deficiency)

Vitamin D deficiency in children presenting to the paediatric orthopaedic clinic, Southampton (2)

Further analysis No specific diagnosis was associated with a high or low vitamin D level There was a lower vitamin D level found in children with unexplained joint pain (mean 22.5) compared to those with other diagnoses (mean 30.7). This was significant p<0.05.

Prevention Infant vitamin D RNIs 8.5 ug/d up to 6 months age 7 ug/d up to age 3 years Chief Medical Officer, 20/1/2011, DOH website “children from the age of six months to five years old should be given a daily 7 micrograms vitamin D supplement”

Prevention: Healthy Start 7.5 ug vitamin D3 Free for some from age 6 months can be given from age 1 month on doctor’s advice Also contain vitamin A and vitamin C Can be bought £1.78/bottle

Healthy start uptake South East 2010

Significance Sunlight exposure 15 – 20 minutes uninterrupted sunlight 3 times per week Vitamin D supplements Vitamin D status sought prior to commencing ‘observation or orthopaedic surgical intervention’

Fractures in 348 children Femur Hand 4.9% 7.5% Tibia/fibula 7.8% Ankle 9.8% Radius/ulna 54.9% Other 1.7% Humerus 13.5%

Fat mass substantially inhibits bone accrual in children with prior fracture JBMR 2009

Summary Majority of active vitamin D from sunlight Increase in cases of symptomatic vitamin D deficiency (not exclusive to poverty/ethnic minorities) Need for raised awareness and improved public health measures