Based on studies in adolescents (Abrams et al., 1997; Andon et al., 1996; Greger et al., 1978, 1979; Schwartz et al., 1973) and the one study in 7- to 9- year-old children (Schofield and Morrell, 1960), a magnesium intake of 5 mg (0.21 mmol)/kg/day appears to have met some but not all the needs of those evaluated. This is the basis for the EAR for children ages 1 through 3 years and 4 through 8 years. For children ages 1 through 3 years with a reference weight of 13 kg (Table 1-3), the EAR is 65 mg (2.7 mmol)/day. For children ages 4 through 8 years with a reference weight of 22 kg, the EAR is 110 mg (4.6 mmol)/day. It is recognized that further studies specific to this age group are needed before more precise EARs can be assigned or distinctions made between males and females or between children of different racial or ethnic groups.

Based on the 1994 CSFII magnesium intake data, adjusted for day-to-day variation (Nusser et al., 1996), the first percentile of intake for children ages 1 through 3 years is 80 mg (3.3 mmol) (see Appendix D), which is above the EAR of 65 mg (2.7 mmol)/day. The median intake for magnesium for this age group is 180 mg (7.5 mmol). For children ages 4 through 8 years, the first percentile of intake is 103 mg (4.3 mmol)/day, slightly below the EAR of 110 mg (4.6 mmol)/day. The median magnesium intake is 206 mg (8.6 mmol)/day.

The variance in requirements cannot be determined from the available data. Thus, a coefficient of variation (CV) of 10 percent is assumed, which results in an RDA for magnesium of 80 mg (3.3 mmol)/day for children ages 1 through 3 years, and an RDA of 130 mg (5.4 mmol)/day for children ages 4 through 8 years.

The Abrams et al. (1997) study provides some data for boys ages 9 through 13 years that leads to the conclusion that boys,