Vitamin d in jordanian infants
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Vitamin D in Jordanian Infants. Najwa Khuri-Bulos Professor of Pediatrics and Infectious Disease Jordan University Hospital. Outline about vitamin D. Sources of vitamin D Classical action on bone Non classical functions Normal vitamin D intake Pts at risk of vitamin D deficiency

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Vitamin D in Jordanian Infants

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Vitamin d in jordanian infants

Vitamin D in Jordanian Infants

Najwa Khuri-Bulos

Professor of Pediatrics and Infectious Disease

Jordan University Hospital


Outline about vitamin d

Outline about vitamin D

  • Sources of vitamin D

  • Classical action on bone

  • Non classical functions

  • Normal vitamin D intake

  • Pts at risk of vitamin D deficiency

  • Clinical manifestations of vitamin D deficiency

  • Laboratory diagnosis of vitamin D deficiency

  • Treatment

  • Status of vitamin D in jordan with special reference to children

    Prevention of vitamin D deficiency


Vitamin d

Vitamin D

  • Rickets first described in the 17th century

  • Relationship to fat soluble vitamin and dietary vitamin D in early 20th century .

  • This is the only vitamin that is synthesized by human body by interaction of skin with sunshine

  • Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D


Vitamin d in jordanian infants

Vitamin D pathways for the two sources of vitamin D


Definition

Definition

  • Vitamin D2, Ergosterol plant sources

  • Vitamin D3 Cholecalciferol from skin

  • also manufactured from lanolin

  • 25,0H vitamin D Calcidiol

  • 1,25 OH vitamin DCalcitriol


Vitamin d actions

Vitamin D actions

  • Vitamin D promotes calcium absorption in the gut

  • Maintains adequate serum calcium and phosphate concentrations to enable normal mineralization of bone and prevents hypocalcemic tetany.

  • It is also needed for bone growth and bone remodeling by osteoblasts and osteoclasts


Vitamin d actions1

Vitamin D actions

Actions on bone

  • Increased Bone density

  • Increased calcium and PO4 deposition

  • Decreased osteoporotic fracture


Vitamin d actions2

Vitamin D actions

Immune response

  • Increased regulatory T cell

  • Increased oxidative burst

  • Increased Cathelicidin

  • Decreased cytokine release


Vitamin d actions3

Vitamin D actions

Pregnancy

  • ?Decreased pre eclampsia

  • Decreased myopathy

  • Decreased calcium malabsorption

  • Decreased bone loss

  • ?Decreased risk of CS

    Mulligan et al,

    American Journal of Obstetric and Gynecology, 2010


Vitamin d action

Vitamin D action

Pancreas

  • Decreased insulin resistance

  • Decreased type 1 diabetes

  • Increased insulin secretion


Vitamin d actions4

Vitamin D actions

Children

  • Decreased SGA

  • Decreased risk of rickets

  • Decreased risk of hypocalcemia

  • Infantile cardiomyopathy if deficient

  • Decreased severity of RSV infection

  • Increased incidence of asthma if deficient


Sources of vitamin d

Sources of vitamin D

  • Normal diets < 10%

  • Must be synthesized by the skin or taken as dietary supplement

    • Skin, must have direct exposure to sunshine 10-15 minutes at noon hours

    • Exposure not acceptable behind glass

    • No sun block applied

    • Dark skin people need more exposure to have same level of vitamin D


Vitamin d in the newborn

Vitamin D in the newborn

  • Highly correlated with vitamin D in the pregnant mother. Fetus totally dependent on maternal sources of vitamin D and Calcium

  • After birth, Breast milk is a very poor source of vitamin D, only 10-40 Units/Litre

  • Hence Must supplement infants very early in life

  • Infants need 400 IU/ per day

  • Even formula fed babies need vitamin D supplementation


Vitamin d status

Vitamin D status

  • 1 nmole/litre =0.4 ngm /ml

  • Vitamin D levels are Inversely related to parathormone levels

  • These level off at 30-40 nanograms determined to be the adequate range

  • Calcium absorption increased at > 30 nanograms


Vitamin d 25 oh levels and vitamin d status

Vitamin D 25 OH levels and vitamin D status

  • Definition

    • <20ng/ml <50 mm/LDeficient

    • 20-30ng/ml 50-75 mm/LInsufficient

    • >30- ng/ml>75 mm/LNormal, optimal

    • >150 ng/ml >375 mm/L Toxic


Vitamin d sources

Vitamin D sources

  • Dietary

  • Supplementation

  • Sunlight

    • Wavelength 290-315 penetrates the skin and converts 7 dehydrocholesterol to previtamin D3

    • Any excess of these is destroyed by sunlight. There is no toxicity from sun exposure.

    • Vitamin D from the skin and dietary sources is metabolized by the liver to become 25 OH and the final 1 hydroxylation step occurs in the kidney to lead to 1, 25 OH vitamin D which is the active form

    • This final renal step is highly regulated by parathormone and serum calcium and PO4 levels


Sun exposure and vitamin d

Sun exposure and vitamin D

  • Ultraviolet (UV) B radiation with a wavelength of 290–320 nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, which in turn becomes vitamin D3.


Adequate intake of vitamin d per day

Adequate intake of vitamin D per day

  • Infants <12 month400 IU

  • Children >1 yr600 IU

  • Adults, pregnant600 IU

  • >70 yrs800 IU

  • Mainly obtained from fish and fortified foods or exposure to sunshine

  • 1 ug=40 units


People at risk of vitamin d deficiency

People at risk of vitamin D deficiency

  • Breast fed infants

  • Older adults

  • People with limited sun exposure

  • People with dark skin

  • People with fat malabsorption

  • People with BMI>30


Causes of vitamin d deficiency in children and adolescents

Causes of vitamin D deficiency in children and adolescents

  • Reduced intake or synthesis of vitamin D3

    • Being born to a vitamin D-deficient mother; dark-skinned women, or women of who actively avoid exposure to sunlight or are veiled

    • Prolonged breastfeeding

    • Dark skin colour

    • Reduced sun exposure — chronic illness or hospitalisation, intellectual disability, and excessive use of sunscreen

    • Low intake of foods containing vitamin D


Causes of vitamin d deficiency in children and adolescents1

Causes of vitamin D deficiency in children and adolescents

  • Abnormal gut function or malabsorption

    • Small-bowel disorders (eg, coeliac disease)

    • Pancreatic insufficiency (eg, cystic fibrosis)

    • Biliary obstruction (eg, biliary atresia)


Causes of vitamin d deficiency in children and adolescents2

Causes of vitamin D deficiency in children and adolescents

  • Reduced synthesis or increased degradation of 25-OHD or 1,25-(OH)2D

    • Chronic liver or renal disease

    • Drugs: rifampicin, isoniazid and anticonvulsants


Osseous signs of vitamin d deficiency common to less common

 Osseous signs of vitamin D deficiency (common to less common)

  • Swelling of wrists and ankles

  • Rachitic rosary (enlarged costochondral joints felt lateral to the nipple line)

  • Genu varum, genu valgum or windswept deformities of the knee

  • Frontal bossing

  • Limb pain and fracture

  • Craniotabes (softening of skull bones, usually evident on palpation of cranial sutures in the first 3 months)

  • Hypocalcaemia — seizures, carpopedal spasm

  • Myopathy, delayed motor development

  • Delayed fontanelle closure

  • Delayed tooth eruption

  • Enamel hypoplasia

  • Raised intracranial pressure

  • secondary hyperparathyroidism


Radiological features

Radiological features

  • Cupping, splaying and fraying of the metaphysis of the ulna, radius and costochondral junction

  • Coarse trabecular pattern of metaphysis

  • Osteopenia

  • Fractures


Treatment of hypocalcemia

Treatment of Hypocalcemia

< 1 month of age

  • 10% calcium gluconate: 0.5 mL/kg (max 20 mL) intravenously over 30–60 minutes.

  • Calcium: 40–80 mg/kg/day (1–2 mmol/kg/day) orally in 4–6 doses,

  • Calcitriol ( vitamin D3) : 50–100 ng/kg/day or in 2–3 doses until serum calcium level is > 2.1 mmol/L or 8 mg/L


Treatment of vitamin d deficiency

Treatment of vitamin D deficiency

Calcitriol , 1, 25 OH vitamin D, Calcidiol, 25 oh vitamin D


Adequate calcium intake

Adequate calcium intake


Recent studies on vitamin d in jordanians

Recent Studies on vitamin D in Jordanians

2011, Batieha Et al Ann Nutr Met

  • 37% females were deficient

  • 5.6% of males were deficient

    2010 Abdul Razzak , Pediatric International

    28% deficient, 16% severe

    Association with breast feeding was found

    National micronutrient survey 2010

    women deficient < 12 ng/ml > 50%

    children 1-6 yrs< 11 ng/ml 10-20%

    Takruri, Khuri-Bulos et al , JMJ, 1-6 yrs also 30% insufficient


Study on newborn and pregnant mothers and vitamin d

Study on newborn and pregnant mothers and vitamin D

  • Ongoing study of vitamin D in newborn

  • More than 3000 vitamin D levels obtained in the first day of life

  • Range from 0.1- 15 ng/ml

  • Cut off for this is 20 ng/ml

  • 99.8 were vitamin D deficient below 10 ng/ml

  • Mean was 3 ng/ml !!!

  • 100 Mothers who were tested also had decreased vitamin D level. Almost uniformly less than 10ng/ml


Vitamin d in jordanian infants

Vitamin D levels in newborns in Jordan

Overwhelming majority >99% are deficient < 15 nanograms/ml


What should be done

What should be done

  • Increased sun exposure, not consistent with current social norms

  • Supplementation of the different age groups

  • Fortification of food items, most useful

  • Which food item?? Oil preferable but flour more feasible since it is cheaper and is the main staple food

  • For infants must give vitamin d drops

  • Pregnant women should be studied further and supplementation during pregnancy must be done


Vitamin d in jordanian infants

Thank you


Vitamin d activity

Vitamin D activity

  • Activated T lymphocytes and macrophages have increased VDR This stimulates antibody mediated and phagocyte mediated cytotoxicity

  • Clinical association with asthma and RSV if cord blood vitamin D is deficient

  • Increased risk of cesarian section also with vitamin D deficiency


Vitamin d in jordanian infants

Metabolism of 25-Hydroxyvitamin D to 1,25-Dihydroxyvitamin D for Nonskeletal Functions.

Holick MF. N Engl J Med 2007;357:266-281.


Vitamin d in jordanian infants

Synthesis and Metabolism of Vitamin D in the Regulation of Calcium, Phosphorus, and Bone Metabolism.

Holick MF. N Engl J Med 2007;357:266-281.


The immune system and vitamin d

The immune system and Vitamin D

  • Calcitriol (I,25, OH) has immune modulating function

  • First described with sarcoidosis

  • Calcitriol produced by macrophages in the granulomas lead to hypercalcemia

  • Calcitriol also inhibits proliferation of MTB in cells

  • This is not subject to feedback as is the kidney

  • Vitamin D deficiency has been shown to increase the risk of infection especially respiratory infection


Vitamin d functions

Vitamin D functions

  • Vitamin D has other roles in the body, including modulation of cell growth, neuromuscular and immune function, and reduction of inflammation

  • Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D

  • Serum concentration of 25(OH)D is the best indicator of vitamin D status. It reflects vitamin D produced cutaneously and that obtained from food and supplements and has a fairly long circulating half-life of 15 days


Sun exposure and vitamin d1

Sun exposure and vitamin D

  • Complete cloud reduces UV energy by 50%; shade

  • UVB radiation does not penetrate glass, so exposure to sunshine indoors through a window does not produce vitamin D

  • Sunscreens with a sun protection factor (SPF) of 8 or more appear to block vitamin D-producing UV rays


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