Estimated secretion in milk^c Increment in RDAs^d,e for the following periods of lactation:

24–40

0.13–0.21

0.21–0.35

0.9–1.5

0.06–0.09

50–83

0.6–1.0

0–6 mo

35

0.5

0.5

5

0.5

100

0.6

6–12 mo

30

0.5

0.4

5

0.5

80

0.6

Comments

Estimated 85% absorption

Increment higher than secretion due to increased energy needs

Estimated 70% utilization for milk production

Increment higher than secretion due to increased energy needs

The milk concentration used by the subcommittee is for unsupplemented women

Estimated 50% absorption; RDA based on 50 rather than 83 µg/liter

RDA based on 0.6 rather than 1.0 µg/liter