Vitamin D and pregnancy
Pregnancy places additional demands on your body. Foetal development and growth increase your body’s requirements for vitamins and minerals. At this time the demand for vitamin D can increase up to 4 to 5 fold.1 Vitamin D is needed to facilitate the availability of extra calcium which is required for growth of the foetal skeleton.1
It is easy to incorporate vitamin D into your daily intake. Simply ensure your skin obtains adequate amounts of sunlight. In the skin UVB rays will convert to vitamin D3 (cholecalciferol).
Pregnant women, especially those who have darker skin tones or wear concealing clothing for cultural or religious reasons have an increased risk of vitamin D insufficiency.2 This group would benefit from vitamin D supplements and possibly diet adjustment. Vitamin D food sources include eggs, butter, mushrooms, sunflower seeds, fatty fish such as herrings, tuna, salmon and sardines, beef, liver and fortified foods such as fortified milk. 3,4
An Australian review in 2010 concluded that women at risk of vitamin D insufficiency should be monitored and appropriately supplemented during pregnancy.1 Vitamin D status should be checked early in pregnancy so that vitamin D insufficiency can be corrected. Your GP will be able to assist with a simple blood test to determine your current vitamin D status and he can suggest appropriate supplementation where necessary.
Vitamin D is an important vitamin for mums and infants. It is essential for the maintenance of health, avoidance of skeletal problems in adults and infants, and cardiovascular and immune health.5 It is also needed for optimal bone mineralisation for children and infants, especially during times when UV sunlight exposure is limited.
Not all mums and infants get enough vitamin D from sunlight. For this group, vitamin D supplementation may be beneficial. A study based on an at-risk population in Sydney made these recommendations for vitamin D supplementation of infants and children in at-risk groups:6
- annual measurement of vitamin D (25(OH)D) in dark-skinned or veiled infants, children and adults
- screening for simple vitamin D insufficiency in the first trimester of pregnancy for dark-skinned or veiled women
- vitamin D supplementation (400IU daily) in breastfed infants of dark-skinned or veiled women until 12 months of age
- preventative daily 400IU vitamin D supplementation in at-risk groups.
Daily sunshine is a great source of vitamin D but whilst obtaining this essential nutrient in this way, it’s important to observe safe sun exposure practices also.
The Australian Bureau of Meteorology website provides a daily UV sunlight forecast for locations around Australia. This information can help you decide the safest times to be in the sun.7
Surprisingly, vitamin D insufficiency in infants is a real concern. In many populations worldwide low vitamin D status or insufficiency has become increasingly recognised as a problem.5 This may be a result of many children and infants not receiving adequate sunlight to synthesize vitamin D in their skin. 5
In Australia and New Zealand, vitamin D insufficiency and nutritional rickets are re-emerging as paediatric health issues in Australia and New Zealand.8
Further demonstrating the prevalence of vitamin D insufficiency in infants, a study was conducted in 2008 among healthy infants and toddlers. Of the 146 participants, 44 (40.0%) had levels below an accepted optimal threshold demonstrating that suboptimal vitamin D status is common among otherwise healthy children.9
Becoming pregnant is dependant on many things; nutritional status of the parents-to-be is one of these. Vitamin D appears to play a part here too. Its potential role in conception and fertility has not been extensively investigated to date and most studies have involved animal models. However, there is evidence to suggest that fertility may be impaired in mothers with low vitamin D.10
Vitamin D status in men is also thought to affect fertility. Dr Anne Clark, medical director at Fertility First assisted reproduction clinic in Sydney, says that from the blood tests of almost 800 men with fertility problems, she has found that almost a third had lower than normal levels of vitamin D. She suggests that this may be a contributing factor to infertility.11
It’s best to prepare your body for pregnancy through good nutrition before becoming pregnant. This will ensure you give your baby the best possible start to life. If you are not confident that you’re vitamin D levels are optimal to support a successful and healthy conception, visit your GP to discuss testing and supplement options.