RCOG Issues New Guidance On Vitamin Supplementation In Pregnancy

Main Category: Pregnancy / Obstetrics
Also Included In: Women's Health / Gynecology
Article Date: 21 Oct 2009 - 4:00 PDT

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The Royal College of Obstetricians and Gynaecologists (RCOG) Scientific Advisory Committee has released a new opinion paper on vitamin supplementation during pregnancy. The paper examines the evidence for vitamin supplementation and provides guidance for pregnant women in the UK. The committee considered the use of multivitamin preparations, as well as the use of high dose individual vitamins for the prevention of specific diseases. The recommendations of the paper are as follows:

Multivitamin and folic acid supplementation:

Pregnant women should be actively encouraged to take folic acid supplementation (400mcg/day) before conception and up to 12 weeks of gestation. Folic acid supplementation has a strong protective effect against neural tube defects. Maternal folic acid supplementation has also been associated with decreased risk of other congenital anomalies, including cardiovascular defects, limb defects and some paediatric cancers such as leukaemia, paediatric brain tumours and neuroblastoma.

Vitamin A

High dose vitamin A supplementation (intake greater than 700mcg/day) is not recommended due to potential teratogenic effects. Pregnant women should also avoid eating liver and liver products, as these may contain high levels of vitamin A.

Vitamin B

Studies have found that vitamin B6 reduces the severity of nausea but not vomiting in the first trimester. Vitamin B6 was also associated with a decrease in the risk of dental decay in pregnant women. However, studies failed to show a positive effect on other obstetric and neonatal outcomes, and the risk of adverse events was difficult to assess. Consequently, there is no strong evidence to support routine vitamin B6 supplementation in pregnancy. Similarly, due to minimal data on the benefits and harms of supplementation with vitamin B1, B2, B3, B5, B7, and B12, there is no strong evidence to support supplementation with any of these vitamins during pregnancy.

Vitamin C and E

Vitamin C is an essential water-soluble vitamin found widely in fruits and vegetables. It plays important roles in collagen synthesis, wound healing, prevention of anaemia and as an antioxidant. Vitamin C is particularly important for pregnant women who are at increased risk of iron deficiency anaemia. A low dose of vitamin C (<200mg) is commonly included in many multivitamin pregnancy preparations.

While there has been considerable interest in the potential use of vitamin C and E to prevent pre-eclampsia, preterm rupture of membranes and fetal growth restriction, recent studies have shown no difference in risk for women given antioxidant supplementation (including vitamin C and E). In the absence of further evidence, routine supplementation with higher dose vitamin C and E is not recommended.

Vitamin D

Severe vitamin D deficiency in pregnancy has been associated with neonatal rickets and reduced bone mineral accrual in childhood. Women at risk of vitamin D deficiency include women of South Asian, African, Caribbean or Middle Eastern family origin, women who have limited exposure to sunlight, women who eat a diet particularly low in vitamin D and women with pre-pregnancy obesity. Women at risk of vitamin D deficiency should take 10 mcg of vitamin D per day.

Vitamin K

Vitamin K comprises a group of fat-soluble vitamins that are involved in blood coagulation. The risk of brain haemorrhage in preterm babies has led researchers to investigate the role of vitamin K supplementation in pregnancy. Recent trials have found that antenatal vitamin K was associated with a non-significant reduction in brain haemorrhage and no improvement in neurodevelopment outcomes in childhood.

Recommendations

Pregnant women should be encouraged to take a multivitamin such as the Healthy Start Vitamin tablet (recommended for pregnancy by the Department of Health/ NHS), which includes 70mg of vitamin C, 400mcg of folic acid and 10 mcg of vitamin D. The Healthy Start Vitamin supplements are free to women on certain benefits (e.g. Income support and/or Child Tax Credit) and to all pregnant women under the age of 18. Some areas also make the supplements available to all pregnant women at low cost. The Department of Health should consider whether provision of free multivitamin supplements for all pregnant women, using doses similar to those in the Healthy Start tablet, would offer public health benefits that outweigh the costs.

In particular, groups at greatest risk of a poor dietary intake of vitamins and with other risk factors, such as obesity, should be targeted for promotion of such supplementation.

Further research is needed to better understand the potential benefits, harms and optimal dose for all vitamin groups.

Notes

To view the Scientific Advisory Committee Opinion Paper, Vitamin Supplementation in Pregnancy, click here.

The NICE clinical guideline, Antenatal care: routine care for the healthy pregnant woman, is available here.

Source
Royal College of Obstetricians and Gynaecologists