The participants were assigned to one of the following interventions:

1,000 milligrams of calcium plus 400 IU of vitamin D3 daily
5 grams of collagen peptides daily
Calcium plus vitamin D3 plus collagen peptides in the aforementioned dosages
Placebo daily

At the end of the trial, skin hydration and skin elasticity were higher (better) and hair loss rate was lower (better) in all 3 intervention groups, compared to the placebo group. There were no effects on body composition, bone health biomarkers, or transepidermal water loss.

Calcium, vitamin D, and collagen for skin and hair health in menopausal women Original paper