These tables show that maternal race/ethnicity, age, education, household income, folic acid supplementation, area of residence, dietary folate intake, and dietary fat consumption were each significantly (p-value < 0.05) associated with nitrate, nitrite, total nitrite, and nitrosamine intake.
The internal rate of return for supplementation in areas where health subcenters are located (142 195 percent) is greater than the IRR in areas without subcenters (59 93 percent), again because of greater delivery costs in those areas.
However, our analysis does not include the fixed costs associated with expanding supplementation in areas currently without subcenter coverage.
Given the difficulties in expanding supplementation to areas without health subcenters, GM fortification of mustard seed is an attractive alternative, and further exploration of this technology is warranted.
22 This limited evidence and the importance of iron prophylaxis in prenatal programmes call for further investigation on the benefits of prenatal iron supplementation in areas of endemic malaria and with a high prevalence of HIV.
Some results suggest that there was a better effect of supplementation in areas with vitamin A deficiency; for example, maternal night blindness seems more prevalent in the Asian trials than in the African trials, where virtually no mothers experienced night blindness.
Alimentary fluoride intake has been studied in children from 6 months to 10 years in cross-sectional and longitudinal studies in order to determine basal fluoride intake from food sources so that fluoride supplementation in areas with low fluoride content in drinking water can be planned at appropriate doses.
However, vitamin D and the case for supplementation remains an area of considerable debate, and further work is still needed to determine both the requirements for health and the relative contributions from diet and from UV exposure to assess whether supplementation would be of benefit.
In 1995 1998, five of the six Belarus regions were classified as having moderate iodine deficiency, whereas the Gomel region, most heavily contaminated with I, was classified as having mild iodine deficiency partly due to some iodine supplementation in this area after the Chernobyl accident (Arinchin et al. 2000).
The cost-effectiveness ratio for expanding supplementation to all areas translates to an internal rate of return of 68 104 percent, which far exceeds the internal rate of return of industrial fortification (6 22 percent) and GM fortification (21 42 percent) (Table 6).
Expanding vitamin A supplementation to all areas was the least costly intervention, at $23 $50 per DALY averted and $1,000 $6,100 per death averted, though cost-effectiveness varied with prevailing health subcenter coverage.
