Table 1.
Characteristics of available eligible trials.
| Author’s Name, Publication Year | Country | Group | Interventions | Dosage | Population Characteristics (Age in Years/Months, Sex: Female/Male) | Baseline Vitamin A Status (μmol/L) | Follow-Up |
|---|---|---|---|---|---|---|---|
| Sivan et al. [26] 2001 |
India | Placebo group | Use of 5 mL groundnut oil for preparation of the noon meal as usual | 0 | Preschool children (--) | -- (8.6% Bitot’s spots) 1 | 40 weeks |
| RPO group | Incorporation of 5 mL RPO into the noon meal after mild seasoning | Provided 5 mL RPO | Preschool children (--) | -- (8.8% Bitot’s spots) | |||
| Stuijvenberg et al. [15] 2001 |
South Africa | Placebo group | A placebo biscuit | 0 | School children (8.7 ± 2.0 years; 48.9:51.1) |
0.721 ± 0.203 (52.6% VAD) 3 |
12 weeks |
| RPO group | A biscuit with RPO | Provided 1.23 mg β-carotene | School children (8.6 ± 2.1 years; 51.9:48.1) |
0.728 ± 0.245 (56.4% VAD) |
|||
| Vitamin A supplement group | A biscuit with synthetic β-carotene | Provided 1.17 mg β-carotene | School children (8.8 ± 2.0 years; 44.6:55.4) |
0.714 ± 0.210 (58.5% VAD) |
|||
| MANORAMA et al. [27] 1996 |
Not mentioned | RPO group | Supplemented with β-carotene in the form of Suji halwa made with 8 g RPO | Provided 8 g RPO | School children (7.6 ± 1.07 years; 1:1) |
0.86 ± 0.45 (66.7% conjunctival xerosis and 33.3% Bitot’s spots) |
60 days |
| Vitamin A supplement group | Supplemented with 600 μg of vitamin A | Provided 600 μg of vitamin A | school children (7.7 ± 1.00 years; 1:1) |
0.74 ± 0.31 (50% conjunctival xerosis and 25.0% Bitot’s spots) |
|||
| Lietz et al. [18] 2001 |
Tanzania | Placebo group | Sunflower oil for use in household food preparations | 0 | Pregnancy women (26.4 ± 6.8 years; 1:0) |
0.91 ± 0.48 (38.7% low vitamin A status 2 and 25% VAD) |
24 weeks |
| RPO group | Received 12 g RPO for use in household food preparations | Provided 12 g RPO | Pregnant women (27.2 ± 5.9 years; 1:0) |
0.96 ± 0.29 (38.7% low vitamin A status and 25% VAD) |
|||
| Canfield et al. [28] 2001 |
Honduras | Placebo group | Received breakfast with placebo capsules | 0 | Lactating mothers (26.0 ± 6.5 years; 1:0) |
1.42 ± 0.34 | 10 days |
| RPO group | Received breakfast mixed with 90 mL RPO. | Provided 90 mL RPO ≈ 90 mg β-carotene |
Lactating mothers (26.0 ± 6.5 years; 1:0) |
1.34 ± 0.23 | |||
| Vitamin A supplement group | Received 90 mg β-carotene capsules | 90 mg β-carotene capsules | Lactating mothers (26.0 ± 6.5 years; 1:0) |
1.28 ± 0.3 | |||
| Placebo group | Breast feeding (mother received placebo capsules) | -- | Infants (7.0 ± 4.0 months; --) |
0.67 ± 0.26 8.8% severe VAD 2 and approximately 50% VAD. |
|||
| RPO group | Breast feeding (mother received RPO) | -- | Infants (7.0 ± 4.0 months; --) |
0.64 ± 0.15 (Consistent with the above) |
|||
| Vitamin A supplement group | Breast feeding (mother received β-carotene capsules) | -- | Infants (7.0 ± 4.0 months; --) |
0.71 ± 0.27 (Consistent with the above) |
|||
| Radhika et al. [16] 2003 |
India | Placebo group | Received 8 mL groundnut oil | 0 | Pregnant women (21.6 ± 2.78 years; 1:0) |
0.93 ± 0.23 4 | 8 weeks |
| RPO group | Received 8 mL RPO | Provided 8 mL RPO ≈ 2173 to 2307 μg β-carotene/day | Pregnant women (21.5 ± 2.74 years; 1:0) |
0.90 ± 0.19 | |||
| Placebo group | Breast feeding (mother received groundnut oil) | -- | Newborn (--) | -- | |||
| RPO group | Breast feeding (mother received RPO) | -- | Newborn (--) | -- | |||
| Mahapatra et al. [29] 1997 |
India | RPO group I | Given 4 g RPO in Besan laddu | Provided 25,000 IU of vitamin A | Children (--) | 0.53 ± 0.12 92% VAD |
15 days |
| RPO group II | Given 8 g RPO in Besan laddu | Provided 50,000 IU of vitamin A | Children (--) | 0.60 ± 0.13 83% VAD |
|||
| Vitamin A supplement group | Given a mega dose of vitamin A. | Provided 50,000 IU | Children (--) | 0.56 ± 0.11 92% VAD |
|||
| Zeba et al. [30] 2006 |
Burkina Faso | Placebo group | With only the regular school lunch | 0 | Pupils (94 ± 20 months; 43:57) |
0.96 ± 0.36 (23.6% VAD) |
7 months |
| RPO group | Received 15 mL RPO in individual meals 3 times a week | Provided 15 mL RPO | Pupils (102 ± 22 months; 49:51) |
0.82 ± 0.30 (40.4% VAD) |
|||
| Vitamin A supplement group | Received a single vitamin A capsule (60 mg) | Provided 60 mg VA capsule | Pupils (101 ± 20 months; 49:51) |
0.77 ± 0.28 (46.1% VAD) |
|||
| Zhang et al. [31] 2003 |
China | RPO group | Received RPO | -- | Men (18–32; 0:1) |
1.48 ± 0.29 | 42 days |
| Placebo group | Received soybean oil | 0 | Men (18–29; 0:1) |
1.30 ± 0.23 |
Note: RPO = red palm oil; -- not mentioned in the article; 1 8.6% Bitot’s spots means 8.6% of participants were suffered from Bitot’s spots; 2 Severe vitamin A deficiency (VAD): serum retinol < 0.35 μmol/L; VAD: serum retinol < 0.70 μmol/L; Low vitamin A status: 0.70~1.05 μmol/L; Normal: serum retinol ≥ 1.05 μmol/L. 3 52.6% VAD means 52.6% of participants were suffered from VAD; 4 There was a reduction of 15.6% in the prevalence of VAD among women with RPO supplementation. In the control group, there was a insignificant drop of 7.9% in the prevalence of VAD. There was no data on baseline VAD.