Table 5.

Weighted means of peak melatonin levels (pg/mL) across ages from the literature

	0–9 years	10–19 years	20–29 years	30–39 years	40–49 years	50–59 years	60–69 years	70–79 years	80–89 years
Melatonin (pg/ml)	155	79.7 ± 25. 8	72.4 ± 27.4	63.8 ± 21.7	63.6 ± 18.7	60.8 ± 28.7	45.2 ± 20.8	33.6 ± 12.4	24.8 ± 7.4
# Studies	2	10	78	42	19	17	15	16	4
(n)	24	118	910	531	250	214	293	362	74

The data are the weighted means ± SD of peak (2400 hours–0300 hours) melatonin levels derived from the literature. # Studies indicate the number of age groups within the 10-year age bands. n = the cumulative number of participants in each age band.