Vitamin D Deficiency in Pregnancy

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Vitamin D Deficiency in Pregnancy
Annie Judkins and Carl Eagleton RNZCGP Conference
Rotorua July 2007
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Newtown Union Health Service

• 20 years of service in south Wellington
• Not for profit, community governed, Primary
  Health Care Service
• Multi Disciplinary Team based care
• Refugee, Mental Health, Maori Community Health,
  Diabetes, Maternal and Child Health Teams

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BACKGROUND

• 10 children with rickets at NUHS 3-4 years
• Re-emergent world wide public and primary health
  epidemic
• Low Vitamin D associated with Rickets, failure
  to thrive, hypocalcaemia, seizures, osteopenia,
  chronic pain and risk of cancers and immune
  system disorders
• No consensus on Vitamin D RDI or treatment
• Melbourne study recommend all dark skinned
  veiled women screened and treated in pregnancy.
  (Nozza Rodda MJA 2001 175)

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Origin of Vitamin D

• Synthesized in the skin
• 7 dehydrocholesterol
• UV light
• Vitamin D3 (Cholecalciferol)
• Vitamin D2 hydroxylation in the liver
• 25-OH Vitamin D
• hydroxylation in the kidney
• 1-25 OH Vit D

Diet
(Ergocalciferol)
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AIMS of Study

• To determine the prevalence of vitamin D
  deficiency in pregnant women accessing our
  service
• To prevent rickets in our community
• To establish a safe and cost-effective protocol
  for screening for and treating vitamin D
  deficiency in our at-risk women

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Method

• All women with positive pregnancy test between
  June 2004-2005 had Vit D level measured
• Screening with PTH, calcium and ALP offered to
  those who were low
• Simple Dietary Questionnaire
• Vitamin D in 1000IU daily
• Vitamin D levels to be checked at delivery.
• Vitadol C prescribed for breast feeding infants.

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RESULTS

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Results - Screening
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Vitamin D by ethnicity - T-tests

• African (p 1.15x10 -5 to -10)
• Middle Eastern (p 0.001- 6.0 x10-6 )
• European (p0.01 - 6.0 x10-6 )
• No significant difference between Maori, PI and
  Asian.
• 9/135 (7) levels lower than recordable accurate
  range

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Average Vitamin D by Ethnicity Season
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Biochemistry Haematology

• Only 10/55 women in this study had a measured
  Calcium lt2.2mmol/l (range 2.05 - 2.58 mmol/l)
• 15 with elevated PTH (gt6)
• Hb Range 87-147 European Hb gtgt all other
  ethnicities in Vitamin D by Hb disappears
  when ethnicity excluded as a variable

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Variables Veiling Diet

• 31 women in study veiled culturally African
  women - average Vit D veiled 10.8 ltltlt unveiled
  18.25nmol/l (p0.008)
• 58/98 drink lt1 glass milk per dayVit D 2
  glasses milk cf nil which disappears when
  ethnicity excluded as a variable

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Variables Housing

• Average Geocode 4.09 geocoding by ethnicity
  AfricanltMIEAltMaoriPIltEuropean
• House gtgt Apartment Dwelling in Vit D by
  housing and geocoding disappears when ethnicity
  is excluded as a variable
• Number of years living in NZ - no difference in
  Vit D

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Treatment Arm of Study

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Results Treatment arm

• 84/141 (60) prescriptions were filled
• 98 Deliveries by team midwives
• 40/98 had Vitamin D levels measured at delivery
• Only 11/40 had level gt50 nmol/l at delivery
• Strike on East Coast USA ports during trial 6
  months.

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Conclusions

• Vitamin D deficiency is the norm in pregnant
  women in our service
• It is not confined to veiled or dark skinned
  women
• 1000 IU daily is safe but not really effective or
  practical due to cost, availability and compliance

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Vitamin D Deficiency Prevention of
RicketsA model of care proposal
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Model of Care Proposal

• Vitamin D treatment for all at risk women
• African, Middle Eastern and all non- European
  others south of the Bombay Hills?
• 50,000 IU monthly - at onset of menarche and
  menstruation
• Adjusted calcium the most cost effective marker
  in at-risk women?

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Study Proposal

• Small study to determine efficacy in higher dose
  treatment during pregnancy 50,000 100,000 IU
  monthly at 28, 32 and 36 weeks gestation
  (Safety demonstrated in high doses Goodenday LS
  et al . Annals Internal Medicine 1971)

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Further study?

• Multi centre study to determine incidence of
  Vitamin D deficiency in pregnant women across
  country

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Thanks to NUHS NUHS Midwives Wellington
Endocrine Society SECPHO Ashleigh Court
Pharmacy Wellington Hospital Laboratory and all
the women who agreed to take part in this study
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Extra for Experts Physiological changes in
Pregnancy

• Serum 25-OH vitamin D
• Serum 1,25-OH vitamin D
• Alkaline phosphatase
• Parathyroid hormone
• Role of other hormones
• Estrogen
• Prolactin
• Growth hormone
• PTHrP, Calcitonin

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Extra for Experts

• The major adaptive process in human and animal
  pregnancy to the demands for calcium is a 2-fold
  increase in the intestinal absorption of calcium.
  This is mediated by increases in
  1,25-dihydroxyvitamin D.
• It has been shown in cross-sectional studies that
  the serum level of 1,25-dihydroxyvitamin D more
  than doubles early in the first trimester in
  human pregnancy.
• These increases are due to increased production
  of 1,25-dihydroxy vitamin D by the maternal
  kidneys, with possibly small contributions from
  maternal decidua, placenta, and fetal kidneys.

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• Almost certainly mediated through 1,25-dihydroxy
  vitamin D there is an increase in intestinal
  Calbindin 9K-D and other proteins. The Calbindin
  9K-D binds calcium and transports it across the
  enterocyte and releases the calcium into the
  circulation. This process is responsible for the
  2-fold increase in intestinal calcium absorption
  early in human pregnancy.
• These adaptations start in advance of the fetal
  demand for calcium, which largely occurs during
  the third trimester.
•  

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Lancet 2001