Melatonin has been shown to stimulate cells called osteoblasts that promote bone growth. Since melatonin levels may be lower in some older individuals such as postmenopausal women, current studies are investigating whether decreased melatonin levels contribute to the development of osteoporosis, and whether treatment with melatonin can help prevent this condition. Melatonin is useful not only in the treatment of sleep disorders, but it is useful in cancer prevention, osteoporosis and, as an adjuvant for weight loss.
Melatonin's therapeutic potential is underestimated because of its wide variety of functional roles and mechanism(s) of action are complex and varied. Melatonin is a chronobiotic agent secreted from the pineal gland during the hours of darkness. Melatonin modulates metabolic and cardiovascular physiology as well as bone metabolism and immune function and detoxification of chemical agents and cancer reduction.
Melatonin levels decrease with age. This decrease in plasma melatonin levels observed in humans during late adulthood may further enhance susceptibility to osteoporosis.
Therapeutic dosages of melatonin seem to be be related to age, gender and co-administration of pain killers. Women need more melatonin than men, opiate users need more melatonin than non-opiate users. To make it even more interesting, individuals with gastrointestinal disorders need substantially more melatonin, as well.
The rule of thumb that I use is:
Ages 10 to 21, starting dose 1 mg for boys, 3 mg for girls.
Ages 21 to 60, starting dose 3 mg for men, 6 mg for women.
For patients taking opiates, and for those patients with GI absorption or motility disorders, 10 mg for both women and men, anticipate 20 mg in women taking opiates.
J Pineal Res. 2006 Nov;41(4):297-305.
Radio NM, Doctor JS, Witt-Enderby PA: Melatonin enhances alkaline phosphatase activity in differentiating human adult mesenchymal stem cells grown in osteogenic medium via MT2 melatonin receptors and the MEK/ERK (1/2) signaling cascade. J. Pineal Res. 2006 May;40(4):332-42.