I was recently discussing with my friends about Vitamin D deficiency in Asian population in UK, when we realised that we were not disucussing this as much in pregnant population as we do in general population. I was more interested in this topic after I read the BJOG article recently on Vit D.
The global consensus is available for routine supplementation in Pregnancy, which is 10 mcg (400 IU) of Vit D in all pregnant women. NICE mentions that it is offered to all pregnant women. But, the most important part is screening for deficiency in pregnancy and the treatment in deficient women, where there seems to be no consensus. However, The ACOG offers clarity in their statement regarding Vit D screening & supplementation.
Screening :
Is it universal or high risk screening? As like in Gestational Dibates (GDM), this confusion still exists. ACOG says that there is no need to screen all pregnant women with a blood test to find out Vit D deficiency. However women at greater risk should be offered a bllood test.
Who are at high risk?
Risk finding is from history and examination of BMI.
Greatest risk is seen in those with
(a) darker skin such as South asian, African, Caribbean, Middle Eastern women
(b) those women with limited exposure to sunlight like housebound and
(c) those with BMI>30.
Defining deficiency :
In nonpregnant, there is a cut-off. However, there is no consensus on an optimal level to maintain overall health in pregnant women.
Most agree that a serum level of at least 20 ng/mL(50 nmol/L) is needed to avoid bone problems. In a Scandinavian Obs & Gyn journal, it was mentioned that Institute of Medicine advises the following serum concentrations of 25-OH-D for defining deficiency: <12 ng/mL (vitamin D deficient), 12–20 ng/mL (vitamin D insufficient), ≥20 ng/mL (vit D sufficient).
When do you test it ? When do you repeat it in pregnancy?
Again there is no consensus. The test is offered mostly in first trimester beacuse the treatment could be started early , once the teratogenic phase (earlyweeks of pregnancy) has passed. The Vit D levels are tested again at 28 weeks gestation.
Much is talked about Vit D deficiency linked to Pre-eclampsia. The recent issue of BJOG (2012) has a RCT with evidence that Vit D levles at mid-trimester is associated with high risk of pre-eclampsia. Hence, in future, we might expect the blood testing in mid-trimester.
What is tested?
For the individual pregnant woman thought to be at increased risk of vitamin D deficiency, the serum concentration of 25-OH-D can be used as an indicator of nutritional vitamin D status.
How and when would you treat it?
The Australian/NZ practice are different to US/Europe. In some aprts of Australia & NZ, the treatmetn for pregnant women with levels 25–50 nmol/L would be to commence 1,000 IU daily and Pregnant women with levels < 25 nmol/L should be commenced 2,000 IU daily. Such consensus is not availble in UK.
When vitamin D deficiency is identified during pregnancy, most experts agree that 1,000–2,000 international units per day of vitamin D is safe. Higher dose regimens used for the treatment of vitamin D deficiency have not been studied during pregnancy.
1 mcg vitamin D (cholecalciferol) = 40 IU
Why is there no rush globally to treat Vit D deficiency in pregnancy unlike in neonates of breastfeeding mothers?
In adults , the calcium metabolism is much dependent on 25-OH levels. So, we would expect that the vit-D defficieny to have impact on foetus.However,
The Calcium and Vit D homeostasis / metabolism in pregnancy is much differnt such that irrespective of maternal Vit D levels, the calcium reaches the foetus due to maternal adaptations during pregnancy. It is only the NEONATE (not the foetus) that becomes calcium-deficient. So, the treatment is always aimed at provisding the neonate with sufficent calcium. hence a nominal Vit-D dosage is chosen instead of intensive treatment in pregnant women - this could be to balance the risk of hypervitaminosis of a fat soluble vitamin.
What about breastfeeding women?
For breastfeeding women, aim for normal levels during pregnancy, then continue on 1,000 IU daily during breastfeeding. We should Consider neonatal supplements in babies with risk factors for low vitamin D.1 mcg vitamin D (cholecalciferol) = 40 IU.
This is my personal review from the data I have read until now on Vit D in pregnancy. If there is any thing changed or to be added , please post in the comment section.
The global consensus is available for routine supplementation in Pregnancy, which is 10 mcg (400 IU) of Vit D in all pregnant women. NICE mentions that it is offered to all pregnant women. But, the most important part is screening for deficiency in pregnancy and the treatment in deficient women, where there seems to be no consensus. However, The ACOG offers clarity in their statement regarding Vit D screening & supplementation.
Screening :
Is it universal or high risk screening? As like in Gestational Dibates (GDM), this confusion still exists. ACOG says that there is no need to screen all pregnant women with a blood test to find out Vit D deficiency. However women at greater risk should be offered a bllood test.
Who are at high risk?
Risk finding is from history and examination of BMI.
Greatest risk is seen in those with
(a) darker skin such as South asian, African, Caribbean, Middle Eastern women
(b) those women with limited exposure to sunlight like housebound and
(c) those with BMI>30.
Defining deficiency :
In nonpregnant, there is a cut-off. However, there is no consensus on an optimal level to maintain overall health in pregnant women.
Most agree that a serum level of at least 20 ng/mL(50 nmol/L) is needed to avoid bone problems. In a Scandinavian Obs & Gyn journal, it was mentioned that Institute of Medicine advises the following serum concentrations of 25-OH-D for defining deficiency: <12 ng/mL (vitamin D deficient), 12–20 ng/mL (vitamin D insufficient), ≥20 ng/mL (vit D sufficient).
When do you test it ? When do you repeat it in pregnancy?
Again there is no consensus. The test is offered mostly in first trimester beacuse the treatment could be started early , once the teratogenic phase (earlyweeks of pregnancy) has passed. The Vit D levels are tested again at 28 weeks gestation.
Much is talked about Vit D deficiency linked to Pre-eclampsia. The recent issue of BJOG (2012) has a RCT with evidence that Vit D levles at mid-trimester is associated with high risk of pre-eclampsia. Hence, in future, we might expect the blood testing in mid-trimester.
What is tested?
For the individual pregnant woman thought to be at increased risk of vitamin D deficiency, the serum concentration of 25-OH-D can be used as an indicator of nutritional vitamin D status.
How and when would you treat it?
The Australian/NZ practice are different to US/Europe. In some aprts of Australia & NZ, the treatmetn for pregnant women with levels 25–50 nmol/L would be to commence 1,000 IU daily and Pregnant women with levels < 25 nmol/L should be commenced 2,000 IU daily. Such consensus is not availble in UK.
When vitamin D deficiency is identified during pregnancy, most experts agree that 1,000–2,000 international units per day of vitamin D is safe. Higher dose regimens used for the treatment of vitamin D deficiency have not been studied during pregnancy.
1 mcg vitamin D (cholecalciferol) = 40 IU
Why is there no rush globally to treat Vit D deficiency in pregnancy unlike in neonates of breastfeeding mothers?
In adults , the calcium metabolism is much dependent on 25-OH levels. So, we would expect that the vit-D defficieny to have impact on foetus.However,
The Calcium and Vit D homeostasis / metabolism in pregnancy is much differnt such that irrespective of maternal Vit D levels, the calcium reaches the foetus due to maternal adaptations during pregnancy. It is only the NEONATE (not the foetus) that becomes calcium-deficient. So, the treatment is always aimed at provisding the neonate with sufficent calcium. hence a nominal Vit-D dosage is chosen instead of intensive treatment in pregnant women - this could be to balance the risk of hypervitaminosis of a fat soluble vitamin.
What about breastfeeding women?
For breastfeeding women, aim for normal levels during pregnancy, then continue on 1,000 IU daily during breastfeeding. We should Consider neonatal supplements in babies with risk factors for low vitamin D.1 mcg vitamin D (cholecalciferol) = 40 IU.
This is my personal review from the data I have read until now on Vit D in pregnancy. If there is any thing changed or to be added , please post in the comment section.
