Belinda Kirkpatrick – Naturopath

abstract from “Avoidance of vitamin D deficiency in pregnancy in the United Kingdom: the case for a unified approach in National policy.” In the July 2010 issue of British Journal of Nutrition.

Key words: Vitamin D, Pregnancy

Vitamin D deficiency is affecting adults in epidemic proportion in Western societies (2). This epidemic is only increased by the Western lifestyle of long work hours indoors, indoor leisure activities and avoidance of sunlight due to the perceived risk of skin cancer (1). Vitamin D deficiency is also more common in women than men, causing an increasing concern during pregnancy, as rickets has re-emerged. Babies born to mothers who are deficient in vitamin D are at an increased risk of developing rickets (3). Current research suggests maternal supplementation of 400 IU vitamin D for prevention (1).

Researchers recently reviewed the history of vitamin D deficiency and rickets in the United Kingdom (1). When vitamin D was discovered in the 1920s, it led to moderate sun exposure for infants and regular cod liver oil supplementation. Vitamin D is a fat-soluble vitamin that is produced naturally when ultraviolet rays from sunlight strike the skin and trigger vitamin D production in the body (4). It is also found naturally in cod liver oil, prompting the recommendations in the 1920s. By the 1930s, rickets had virtually disappeared in the UK (1). In the 1990s, cod liver oil lost favor when high levels of vitamin A (found naturally in cod liver oil, though at moderate levels), were found to cause birth defects. Since then, no further recommendations were made on supplementing vitamin D and now a resurgence of rickets is being seen (1).

The importance of vitamin D during pregnancy is also supported by the increased number of vitamin D receptors on pregnancy-specific tissues, such as the placenta (5). As well as, the correlation between low maternal levels of vitamin D and an increased prevalence of pre-eclampsia and miscarriage (1).

The current research found that 90% of white pregnant women living in the South of England had vitamin D (25(OH)D) concentrations below the recommended level (<50nmol/l; approximately 403,000 women) during the winter and spring months; 28% were seriously deficient (<25nmol/l; over 150,000 women); and no one reached 75 nmol/l, which is currently considered the optimal level (1). Because of the high prevalence of vitamin D deficiency,  the recommendation of supplementation with 400 IU/day of vitamin D for pregnant women in the United Kingdom was proposed (1).

In conclusion, vitamin D deficiency is reaching record levels in Western societies. This is causing a major concern in pregnant women and increasing the risk of children born with rickets. New guidelines in the United Kingdom recommend supplementation of 400 IU/day (1). Further research needs to be done to establish potential benefits of higher levels of maternal vitamin D intakes (1).

REFERENCES:
1. Hypponen E, Boucher B. Avoidance of vitamin D deficiency in pregnancy in the United Kingdom: the case for a unified approach in National policy. Doi:10.1017/S0007114510002436.
2. Prentice A. Vitamin D deficiency: a global perspective. Nutr Rev 10 Suppl. 2, 66, S153-164.
3. Holick MF (2006) Resurrection of vitamin D deficiency and rickets. J Clin Invest 116, 2062-2072.
4. Dietary Supplement Fact Sheet: Vitamin D (NIH). http://ods.od.nih.gov/factsheets/vitamind.asp
5. Evans KN, et al. Vitamin D and placental-decidual function. J Soc Gynecol Investig 2004. 11:263-271.

Iodine deficiency in pregnancy can lead to a wide range of neurological defects including problems with auditory and cognitive function.  In 2009, researchers looked at the iodine status of Australian pregnant women. (Charlton KE, Gemming L, Yeatman H, Ma G. Suboptimal iodine status of Australian pregnant women reflects poor knowledge and practices related to iodine nutrition. Nutrition 2010 Jan 14).

When iodine status was assessed: 85.5% of the women had INADEQUATE iodine status; 10.9% were adequate; 3.6% were more than adequate; 0% had an excessive level of iodine.

For those of you who have done preconception or pregnancy care with me – you will now know why I am always testing your urinary iodine levels!

Iodine is also important for many other body functions and is vital for proper thyroid function. If you have not already been tested, make an appointment now to have your iodine status and diet assessed.