There are a few more ingredients in cow’s milk that also help your nail health, namely B vitamins, iron, magnesium, and zinc. One cup of whole milk contains 46% of your recommended daily amount (RDA) of vitamin B12, 7% of your RDA of magnesium, 11% of your RDA of zinc, and 0.073 milligrams of iron.
Your nails need vitamin B12 for iron absorption and to keep them strong and healthy. In fact, according to a 2018 study published in BMJ Case Reports, a vitamin B12 deficiency could manifest in bluish discoloration and darkened streaks on your nails.
You need magnesium for protein synthesis and to prevent ridges on your nails. Zinc ensures that your nails keep growing the way they’re supposed to. Per a 2013 study published in the International Journal of Trichology, zinc deficiency could lead to a decrease in nail growth rate and fragile and brittle nails. It could also contribute toward the degeneration of your nail bed and white spots on the surface. Your nails need iron for the same reason the rest of your body needs iron — to transport oxygen to where it needs to go. Iron is a key part of red blood cells. If you have anemia (not enough healthy red blood cells), your nails might be concave or have vertical ridges on them.
Cow’s milk benefits aside, however, what happens to your body when you drink milk every day? Are there concerns?