A randomized, double blind trial reported on January 26, 2017 in the journal Aging found benefits for a combination of melatonin, strontium citrate, vitamin D3 and vitamin K2 in postmenopausal women with osteopenia (subnormal bone density), a precursor to osteoporosis.

Eleven women received a placebo and an equal number received 5 milligrams (mg) melatonin, 450 mg strontium, 2000 international units vitamin D3 and 60 micrograms K2 (a combination designated as MSDK) nightly for one year. Bone mineral density, serum 25-hydroxyvitamin D and C-reactive protein (CRP, a marker of inflammation) levels were measured at the beginning and end of the study. Bone turnover rate was assessed by the evaluation of serum markers in blood samples collected at baseline and months 6 and 12.

At the trial's conclusion, those who received the nutritional supplements experienced a 4.3% average increase in bone mineral density in the lumbar spine, a 2.2% increase in femoral neck density and a trend toward an increase in total left hip density, along with an elevation in a marker of bone formation and a reduction in bone turnover in comparison with the placebo group. Mood and quality of sleep also improved among those who received the nutrients, and CRP levels significantly declined. Ten year vertebral fracture risk probability declined by 6.48% among the group that received the nutrients, while increasing by 10.8% among those who received a placebo.

“Based on the fact that MSDK treatment did not completely inhibit osteoclastogenesis, we conclude that MSDK is favoring bone remodeling to proceed towards equilibrium by allowing osteoclastogenesis to some extent,” the authors write.  “These findings provide both clinical and mechanistic support for the use of MSDK for the prevention or treatment of osteopenia, osteoporosis or other bone‐related diseases.”