Safety of vitamin D treatment doses in pregnancy

Routine supplementation of vitamin D at doses of 400units (10micrograms) per day is currently recommended for pregnant women. Higher doses of vitamin D for treating deficiency may be considered in a pregnant woman if local laboratory results indicate a need for treatment.

Prescribers should always refer to general guidance before prescribing in pregnancy.

Treatment regimens

Consult local guidance in the first instance.

The optimal dose to correct vitamin D deficiency safely in pregnancy is still not clear from the available data and evidence.

UK guidance

There is currently no UK guidance on managing vitamin D deficiency in pregnancy.

International guidance

International guidance recommends a daily intake of 1,000-2,000units, with upper limits of 4,000units daily advised in the American College of Obstetricians and Gynaecologists (ACOG) guidelines.

In certain situations higher doses may be used or recommended by specialists.

Very high single bolus doses of intramuscular vitamin D (300,000-500,000 units) would only ever be considered in specialist settings and are not generally recommended in pregnant women.

Monitoring following treatment

The decision to treat vitamin D deficiency should be based on local laboratory findings and be guided by local vitamin D reference ranges.

The ACOG make no recommendations in their guidance around monitoring of serum calcium or vitamin D levels following treatment with vitamin D in pregnancy.

Accepted practice

In the general population, vitamin D levels can be checked around 3-6 months after starting treatment when steady state levels are likely to have been attained. NICE recommend checking adjusted plasma calcium one month after completing the loading regimen or after starting lower dose vitamin D supplementation in case primary hyperparathyroidism has been unmasked.

Neonatal monitoring

It may be reasonable to check neonatal calcium and vitamin D levels at delivery if there are concerns about these.

Preferred forms of vitamin D

Colecalciferol and ergocalciferol are the preferred forms of vitamin D to treat deficiency.

The Electronic Medicines Compendium (eMC) provides a list of UK products and prescribing information, including vitamin D products that are licensed for treatment of vitamin D deficiency during pregnancy. Note that some manufacturers of colecalciferol preparations state they can be taken during pregnancy when strictly indicated to correct vitamin D deficiency.

Combined calcium and vitamin D products are not routinely used to correct vitamin D deficiency in pregnancy but may have a role in women at high risk of pre-eclampsia.

Further information

UKTIS provide detailed information on the safety of Vitamin D in pregnancy for healthcare professionals (registration required).

The UKTIS has also produced a patient friendly factsheet (freely available) to inform expectant mothers about the safety of taking vitamin D during pregnancy.

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