I have been researching alittle about Vitamin D during pregnancy and I have to say, there's a wealth of conflicting evidence out there. Here is a study that doesn't support Vitamin D deficiency, revised 10 February 2011.


Systematic review of first trimester vitamin D normative levels and outcomes of pregnancy

Objective:
We undertook a systematic review to assess normative levels of vitamin D in early pregnancy and association with subsequent pregnancy outcomes.

Study design:
Medline, Embase databases and reference lists were searched. Inclusion criteria were pregnant populations, blood sample taken during first trimester and serum hydroxyvitamin D levels assessed.

Results:
Eighteen studies reported vitamin D levels in first trimester (n=11-3730), and five examined pregnancy outcomes. Mean vitamin D concentrations differed when stratified by ethnicity; Caucasian (mean(SD): 29.4(11.7)– 73.1(27.1) nmol/L) and non-Caucasian (15.2(12.1)– 43(12) nmol/L). Most studies used general population cut-points to define deficiency and found a large proportion of women ‘deficient’. Two articles examined risk of preeclampsia and reported differing findings, while two of three found low levels associated with increased risk of small-for-gestational age births.

Conclusion:
There is no clear definition of vitamin D deficiency in pregnancy and insufficient evidence to suggest low vitamin D levels in early pregnancy are associated with adverse pregnancy outcomes.
[link to www.sciencedirect.com]


The main reason (that I have found so far) why there is alot conflicting evidence about Vitamin D deficiency is due to MONEY.


I can't really complain. First, this is America and I suspect the quickest way to treat the massive vitamin D deficiency pandemic is going to be through private industry, like it or not. Second, it is possible one of the vitamin D knockoff drugs will actually work better than vitamin D; "possible" I said. Third, I get royalties on my own brand of vitamin D so I have my own conflicts of interest.
[link to www.naturalnews.com]


Vitamin D deficiency during pregnancy is a very real concern, but there is more evidence to support the need for at least 4,000 IU Vitamin D a day, then against it. The only problem I now have is whether Vitamin D supplements should be used at all. Here is a paper that supports and recommends Vitamin D supplements.


High-dose vitamin D3 supplementation in a cohort of breastfeeding mothers and their infants: a 6-month follow-up pilot study.

OBJECTIVE:
To examine the effect of high-dose maternal vitamin D(3) (vitD) supplementation on the nutritional vitD status of breastfeeding (BF) women and their infants compared with maternal and infant controls receiving 400 and 300 IU vitD/day, respectively.

DESIGN:
Fully lactating women (n = 19) were enrolled at 1-month postpartum into a randomized- control pilot trial. Each mother received one of two treatments for a 6-month study period: 0 or 6000 IU vitD(3) plus a prenatal vitamin containing 400 IU vitD(3). The infants of mothers assigned to the control group received 300 IU vitD(3)/day; those infants of mothers in the high-dose group received 0 IU (placebo). Maternal serum and milk vitD and 25(OH)D were measured at baseline then monthly; infant serum vitD and 25(OH)D were measured at baseline, and months 4 and 7. Urinary calcium/creatinine ratios were measured monthly in both mothers and infants. Dietary and BF history and outdoor activity questionnaires were completed at each visit. Changes in skin pigmentation were measured by spectrophotometry. Data were analyzed using chi-square, t-test, and analysis of variance (ANOVA) on an intent-to-treat basis.

RESULTS:
High-dose (6400 IU/day) vitD(3) safely and significantly increased maternal circulating 25(OH)D and vitD from baseline compared to controls (p < 0.0028 and 0.0043, respectively). Mean milk antirachitic activity of mothers receiving 400 IU vitD/day decreased to a nadir of 45.6 at visit four and varied little during the study period (45.6-78.6 IU/L), whereas the mean activity in the 6400 IU/day group increased from 82 to 873 IU/L (p < 0.0003). There were no differences in circulating 25(OH)D levels of infants supplemented with oral vitD versus infants whose only source of vitD was breast milk.

CONCLUSION:
With limited sun exposure, an intake of 400 IU/day vitamin D(3) did not sustain circulating maternal 25(OH)D levels, and thus, supplied only extremely limited amounts of vitamin D to the nursing infant via breast milk. Infant levels achieved exclusively through maternal supplementation were equivalent to levels in infants who received oral vitamin D supplementation. Thus, a maternal intake of 6400 IU/day vitamin D elevated circulating 25(OH)D in both mother and nursing infant.
[link to www.ncbi.nlm.nih.gov]


My concern with this study is that, as I have posted earlier, they get royalties for selling their own brand of vitamin D supplements. This leads me to believe that money is their drive, so these supplements cannot be trusted. Vitamin D deficiency is alot higher where I live (UK), due to the lack of sun, especially in winter and spring.

After alittle digging around I have found 'other' ways to keep your Vitamin D levels up. There are two natural ways you can get vitamin D...

* Your body makes vitamin D in response to sunlight.
* You can get vitamin D from your food and drink.

Our main source of vitamin D is that made by our own bodies. 90% of our vitamin D is made in the skin with the help of sunlight.

Ultraviolet B (UVB) sunlight rays convert cholesterol in the skin into vitamin D. Darker skins need more sun to get the same amount of vitamin D as a fair-skinned person. The sunlight needed has to fall directly on to bare skin (through a window is not enough). 2-3 exposures of sunlight per week in the summer months (April to September) are enough to achieve healthy vitamin D levels that last through the year. Each episode should be 20-30 minutes to bare arms and face. This is not the same as suntanning; the skin simply needs to be exposed to sunlight.

Good sources of vitamin D in food include: oily fish such as salmon, mackerel and sardines, and foods fortified with vitamin D such as margarine and some breakfast cereals. Red meat and egg yolk also provide a little vitamin D.

I'm still researching this topic, so my conculsions on supplements arn't final!!