***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: To study the effect of calcium and vitamin D supplementation on the incidence of toxaemia of pregnancy , 200 r and omly selected pregnant women ( supplemented group ) , were put on calcium ( 375 mg/day ) and vitamin D ( 1,200 IU/day ) supplements at 20 - 24 weeks of pregnancy onwards . Another 200 pregnant women constituted the non-supplemented group . At 32 and 36 weeks of pregnancy the systolic and diastolic blood pressure of non-toxemic women was significantly lower in the supplemented group than in the non-supplemented group . However , the incidence of toxaemia in the supplemented group ( 6 % ) was not significantly different from that in the non-supplemented group ( 9 % ) OBJECTIVES Using an angiotensin sensitivity test we carried out a prospect i ve study in an attempt to predict the possible onset of preeclampsia and to prevent it by calcium supplementation ( elemental calcium 156 or 312 mg/day per os ) and treatment with vitamin D3 ( 0.5 micrograms/3 day per os ) . METHOD We used a study design in which 666 singleton pregnant women were managed with conventional antenatal care and 210 singleton pregnant women were managed with a protocol , together with conventional antenatal care .  RESULT Of the 666 women managed conventionally , 113 ( 16.9 % ) developed preeclampsia . However , the incidence of preeclampsia in the 210 women managed on the protocol was lower , at 10.9 % . CONCLUSION Our findings indicate that this protocol for the prediction and prevention of preeclampsia is useful for pregnant women at high risk of developing preeclampsia OBJECTIVE Improve vitamin D status in lactating women and their recipient infants , and measure breast milk calcium concentration [ Ca ] as a function of vitamin D regimen . DESIGN / METHODS Fully breastfeeding mothers were r and omized at 1 month postpartum to 2000 ( n = 12 ) or 4000 ( n = 13 ) IU/day vitamin D for 3 months to achieve optimal vitamin D status [ serum 25(OH)D > or = 32 ng/mL ( 80 nmol/L ) ] . Breast milk [ Ca ] , maternal and infant serum 25(OH)D and serum Ca , and maternal urinary Ca/Cr ratio were measured monthly . RESULTS Mothers were similar between groups for age , race , gestation , and birth weight . 25(OH)D increased from 1 to 4 months in both groups ( mean + /- SD ) : + 11.5 + /- 2.3 ng/mL for group 2000 ( p = 0.002 ) and + 14.4 + /- 3.0 ng/mL for group 4000 ( p = 0.0008 ) . The 4000 IU/day regimen was more effective in raising both maternal and infant serum levels and breast milk antirachitic activity than the 2000 IU/day regimen . Breast milk [ Ca ] fell with continued lactation through 4 months in the 2000 and 4000 IU groups . Decline in breast milk [ Ca ] was not associated with vitamin D dose ( p = 0.73 ) or maternal 25(OH)D ( p = 0.94 ) . No mother or infant experienced vitamin D-related adverse events , and all laboratory parameters remained in the normal range . CONCLUSION High-dose vitamin D was effective in increasing 25(OH)D levels in fully breastfeeding mothers to optimal levels without evidence of toxicity . Breast milk [ Ca ] and its decline in both groups during 1 to 4 months were independent of maternal vitamin D status and regimen . Both the mother and her infant attained improved vitamin D status and maintained normal [ Ca ] PURPOSE We sought to examine associations of first-trimester intake of calcium , n-3 and n-6 fatty acids , trans fatty acids , magnesium , folate , and vitamins C , D , and E with  preeclampsia ( PE ) and gestational hypertension ( GH ) . METHODS We studied associations of diet with PE or GH among 1718 women in the prospect i ve cohort study Project Viva , using logistic regression and adjusting for maternal age , prepregnancy body mass index , first trimester systolic blood pressure , race/ethnicity , education , and parity . We assessed first-trimester diet using a vali date d semiquantitative food frequency question naire . RESULTS A total of 59 ( 3 % ) women developed PE , and 119 developed ( 7 % ) GH . We found a somewhat-lower risk of PE associated with higher intake of the elongated n-3 fatty acids docosahexaenoic and eicosapentaenoic acids ( odds ratio [ OR ] 0.84 , 95 % confidence interval [ 95 % CI ] : 0.69 - 1.03 per 100 mg/day ) , fish ( OR 0.91 , 95 % CI 0.75 - 1.09 per serving/day ) , and the ratio of docosahexaenoic + eicosapentaenoic to arachadonic acid ( OR 0.82 , 95 % CI 0.66 - 1.01 ) . We did not observe a lower risk of GH or PE with a greater intake of calcium ; vitamin C , D , or E ; milk ; magnesium ; folate ; or with lower intake of n-6 or trans fatty acids . CONCLUSIONS Our results support a potential benefit for elongated n-3 fatty acids in preventing preeclampsia 
    Output:
    
The studies included in this review show conflicting results about the association of vitamin D levels and the risk of preeclampsia .