Transcript Vitamin D deficiency in children

Vitamin D deficiency in
children
Dr. Rim El-Rifai
Consultant Paediatrician
Queen Mary’s Hospital for Children
Dangers of Vitamin D deficiency:
DOH February 2012
 Up to ¼ of the population has low levels of Vitamin D in
their blood
 The majority of pregnant women do not take Vitamin D
supplements
 People on lower income can get supplements through
the Healthy Start Scheme
Vitamin D
 A prohormone essential for normal absorption of
calcium from the gut
 It occurs Naturally in the body following exposure to
UVB sunlight, the body can also synthesize it (from
cholesterol)
 A group of fat-soluble Secosteroids
 In humans, it can be ingested as cholecalciferol
(vitamin D3) or ergocalciferol (vitamin D2)
25-hydroxy vitamin D
 The 25-hydroxy vitamin D test is the most accurate way
to measure vitamin D level.
 In the kidney, 25-hydroxy vitamin D changes into an
active form of the vitamin.
Synthesis of
Vitamin D
In the skin 7-dehydrocholseterol is converted to
vitamin D3
In the liver vitamin D is converted to 25hydroxycholecalciferol, or 25-hydroxyvitamin D
(Calcidiol) —abbreviated 25(OH)D: the specific
vitamin D metabolite measured in serum to
determine a vitamin D status.
Part of the calcidiol is converted by the kidneys to
1, 25- dihydroxy vitamin D3 (Calcitriol), the
biologically active form of vitamin D.
Calcitriol circulates in the blood, regulating the
concentration of Calcium and Phosphate in the
bloodstream and promoting the healthy growth
and remodeling of bone.
Calcidiol is also converted to calcitriol outside of
the kidneys for other purposes, such as the
proliferation, differentiation and apoptosis of cells;
calcitriol also affects neuromuscular function and
inflammation.[
Vitamin D deficiency in Children in
the UK ADCH 2007
 Survey of Paediatricians in the West Midlands in 2001
 24 cases of Vit D deficiency under 5 years of age
 Overall incidence 7.5 per 100 000
 11/24 had bowed legs, presented at around 18 months
 6 had hypocalcemic seizures at 6 weeks of age
 4 had gross motor delay at 17.7 months of age
 All were black African or African-Caribbean
 Majority were beastfed
 50% of those with convulsions were formula fed suggesting inadequate Vit D
content in formula milk
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Advised: need to supplement vulnerable groups including pregnant women
Vitamin D deficiency rickets
among children in Canada
 Paediatricians surveyed between 2002-2004
 104 confirmed cases in the study period
 Overall annual incidence 2.9 cases per 100 000
 Mean age at diagnosis 1.4 yrs
 65% lived in urban areas
 89% had intermediate or darker skin
 94% were breastfed
 None of the breast fed babies had received a supplement according
to guidelines (400 IU/day)
 Maternal risk factors included: limited sun exposure, lack of Vit D from
diet, lack of Vitamin supplementation during pregnancy and lactation
AMERICAN ACADEMY OF PEDIATRICS
Prevention of Rickets and Vitamin D Deficiency: New
Guidelines for Vitamin D Intake, April 2003
 Cases of rickets in infants attributable to inadequate vitamin
D intake and decreased exposure to sunlight continue to be
reported in the United States.
 A state of deficiency occurs months before rickets is obvious
on physical examination.
 Also, it is acknowledged that most vitamin D in older children
and adolescents is supplied by sunlight exposure. However,
dermatologists and cancer experts advise caution in
exposure to sun, especially in childhood, and recommend
regular use of sunscreens.
 Sunscreens markedly decrease vitamin D production in the
skin.
People at risk of Vit D deficiency
 all pregnant and breastfeeding women, especially teenagers
and young women
 infants and young children under 5 years of age
 older people aged 65 years and over
 people who have low or no exposure to the sun, for example
those who cover their skin for cultural reasons, who are
housebound or confined indoors for long periods
 people who have darker skin, for example people of African,
African-Caribbean and South Asian origin
Presentation
 Extremely variable and dependent on:
 age
 Severity of deficiency
 Underlying causes
 Ranges from Biochemical to severe bony disease
Rickets in 1st year of life
 The most rapidly growing bones are : skull, upper limbs and
ribs
 Craniotabes
 Widening on cranial sutures
 Frontal bossing
 Enlarged swollen epiphyses: particularly wrists
 Bulging of costo-chondral joints (Rachitic Rosary)
 Harrison’s sulcus
 Irritability
 Hypotonia
Bowing of legs
Frontal bossing
Rachitic Rosary
Enlarged Swollen Epiphyses
Rickets after the first year
 Genu Varum, Genu Valgum
 Abnormal dentition with enamel hypoplasia
 Bone pain
 Proxymal myopathy
Genu Valgum and Genu Varum
Severe Rickets
In severe cases resulting from low Calcium:
 Tetany
 Laryngeal stridor
 Paraesthesiae
 Convulsions
 Respiratory failure
Association of subclinical vitamin D deficiency
with severe acute lower respiratory infection in
children
 Study of 150 hospitalized Indian children in 2004
 Subclinical vitamin D deficiency and non-exclusive
breast feeding in the first 4 months of age:
 significant risk factors for severe acute lower respiratory
infections in Indian children
Causes of Vitamin D deficiency
 Poor dietary intake most common in Asian population
 Reduced synthesis from sun exposure
 Genetic:
 Vitamin D dependent rickets: AR
 Hypophosphataemic Rickets: x-linked dominany
 Malabsorption: Coeliac disease, Cystic Fibrosis
 Renal disease (low 1,25 dihydroxy vitamin D- the most active
form)
 Liver Disease
 Medications such as Anticonvulsants induce hepatic enzymes
Calciopenic: Low Ca
• Dietary calcium and vitamin D deficiency
 Malabsorption
 Lack of sun light
 Hepatic disease
 Anticonvulsant treatment
 Renal disease
 1-α hydroxylase deficiency
 End organ resistance to vitamin D
Phosphopenic:low PO4
 Fanconi Syndrome
 X-linked hypoposphataemic rickets
 Renal tubular acidosis
 Ocul-cerebro-renal syndrome (Lowe syndrome)
 Osteopenia of prematurity
Biochemical
 Hypocalcaemia
 Hypophosphataemia
 Elevated Alkaline Phosphatase
 Low 1,25 – Dihydroxy vitamin D
 Serum Parathyroid Hormone level may be high
Radiologically
 Widening of growth plate
 Fraying, Cupping, and Widening of metaphyses
 Pseudo fractures
 Signs of secondary hyperparathyroidism :
subperiosteal erosion
Other investigations
 Depending on underlying cause:
 Acidosis
 Aminoaciduria
 Chronic renal failure
 anaemia
Treatment
 Calcium, phosphate and vitamin D given in varying
combinations
 Underlying abnormalities need to be treated (coeliac
disease)
 Growth needs to be monitored
 In hypophsphataemic rickets large doses of Vitamin D are
required
 In 1α hydroxylase deficiency or end-organ resistance to
vitamin D, 1,25- dihydroxy-cholecalciferol is usually required
in significant doses
 Regular renal USS is important
Treatment
 Vitamin D 1,000 to 5,000 μg IV/ day until normal
alkaline phosphatase
 Then 10 μg / day and 500 ml/ day of milk for calcium
requirements
 Exposure to sunlight
 Dietary source: oily fish, fortified margarine
Dietary sources
 Oily fish
 Eggs
 Infant formula
 Some cereals, dairy products, low fat speads have a
small amounts added
 Difficult to get sufficient Vitamin D from diet alone
Breast feeding and Vitamin D
 Infants who are breastfed but do not receive
supplemental vitamin D or adequate sunlight exposure
are at increased risk of developing vitamin D deficiency
or rickets.
 Human milk typically contains a vitamin D
concentration of 25 IU/L or less.
 The recommended adequate intake of vitamin D
cannot be met with human milk as the sole source of
vitamin D for the breastfeeding infant.
Formulas and Vitamin D
 All infant formulas must have a minimum vitamin D
concentration of 40 IU/100 kcal (258 IU/L of a 20kcal/oz formula) and a maximum vitamin D
concentration of 100 IU/100 kcal (666 IU/L of a 20kcal/oz formula).
 All formulas sold have at least 400 IU/L.
 If an infant is ingesting at least 500 mL per day of
formula (vitamin D concentration of 400 IU/L), he or she
will receive the recommended vitamin D intake of 200
IU per day.
Sunlight Exposure
 Decreased sunlight exposure occurs:
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during the winter and other seasons and when sunlight is attenuated by clouds,
air pollution
Lifestyles or cultural practices:
 decreased time spent outdoors
 increase the amount of body surface area covered by clothing when outdoors.
individuals with darker skin pigmentation
by the use of sunscreens.
 Skin Cancer:
 age at which direct sunlight exposure is initiated is more important than the
total sunlight exposure over a lifetime in determining the risk of skin cancer.
 AAP guidelines for decreasing exposure:
 infants younger than 6 months should be kept out of direct sunlight,
 children’s activities that minimize sunlight exposure should be selected,
 protective clothing as well as sunscreens should be used.
Chief Medical Officers:
 “A significant proportion of people in the UK probably
have inadequate levels of vitamin D in their blood.
 “People at risk of vitamin D deficiency, including
pregnant women and children under 5, are already
advised to take daily supplements”.
 DOH February 2012
National Pharmacy Association
 Fact sheet prepared with assistance of DOH in March
2012
 Providing advice on the prevention of vitamin D
Deficiency in the at risk groups
 http://www.npa.co.uk/resources/information-leafletsand-factsheets/clinical/preventing-vitamin-d-deficiencyin-at-risk-groups/
NPA Recommendations
 Daily vitamin D supplementation should be taken by:
 All pregnant and breastfeeding women
 Breastfed infants from one month of age if mother did
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not take vit D supplements through pregnancy
All children aged 6 mon- 5 years (except who receive
more than 500 ml of formula milk, which is fortified with
Vit D)
People aged 65 and over
People who are not exposed to much sun
People with darker skins
Medical conditions (GI, renal, liver)
Medication (Carbamazepine, phenytoin, primidone,
barbiturates, some anti-HIV medicines
NPA Supplementation guidance
Patient Class
Daily supplementation dose of
vitamin D
Pregnant or breastfeeding
10 micrograms (440 iu)
Breastfed infants from one month of
age if mother did not take vitamin D
supplementation during pregnancy
Babies may need supplementation in
the form of vitamin drops containing
vitamin D
Children aged 6 mon to 5 yrs drinking
500 ml or more of formula milk
None required
Children 6 mon to 5 yrs NOT drinking
500 ml of formula milk
Vitamin drops containing vitamin D
Aged 65 years or all ages with limited
exposure to sun
10 micrograms (400 iu)
prognosis
 Excellent in most children
 Dependent on compliance with treatment
 Less certain in hypophospahtaemic rickets and severe
deformities of the limbs may result