Table 1.
Nutritional factors with significant associations with risk of developing pre-eclampsia (95 % confidence intervals)
| Dietary or nutritional factor | Effect estimate | 95 % CI | Number of studies | Number of participants | I 2 | Quality of evidence |
|---|---|---|---|---|---|---|
| 25(OH)D < 50 mmol/l(12,35) | OR 2·11 | 1·52, 2·94 | 6 | 2008 | 0 % | High |
| Serum Fe(12,32) | OR 9·97 | 4·00, 24·9 | 23 | 1912 | 96 % | High |
| Serum Zn* (12,33) | OR 0·35 | 0·17, 0·68 | 14 | 1091 | 88 % | High |
| Serum vitamin C* (12,34) | OR 0·37 | 0·22, 0·61 | 29 | 2777 | 91 % | Moderate |
| Serum vitamin E* (12,34) | OR 0·46 | 0·27, 0·79 | 34 | 3398 | 93 % | Moderate |
| Serum vitamin B12 (36) | WMD − 15·24 pg/ml | -27·52, −2·954 | 19 | 3211 | 98 % | Low |
| Serum Se(51) | SMD – 0·85 | -1·46, −0·25 | 26 | 5583 | 96 % | Low |
| Vitamin D supplementation* (31,37) | RR 0·62 | 0·43, 0·91 | 12 | 1353 | 0 % | High |
| Vitamin D and Ca supplementation* (31,37) | RR 0·49 | 0·31, 0·77 | 3 | 1120 | 0 % | High |
| Ca supplementation(52) | RR 0·49 | 0·39, 0·61 | 30 | 20 445 | 59 % | Moderate |
| Mg supplementation* (53) | RR 0·76 | 0·59, 0·98 | 7 | 2653 | 1 % | Moderate |
| Multiple micronutrient supplementation* (31) | RR 0·40 | 0·27, 0·59 | 2 | 510 | 0 % | Low |
| Healthy maternal dietary pattern* (39) | OR 0·78 | 0·70, 0·86 | 4 | 126 811 | 39 % | High |
| Ultra-processed foods dietary pattern(54) | OR 1·28 | 1·15, 1·42 | 4 | 112 307 | 0 % | High |
RR, relative risk; WMD, weighted mean difference; SMD, standardised mean difference; NA, not applicable.
*
Protective against developing pre-eclampsia.