Women who drink a lot of milk during pregnancy may lower their baby's risk of developing multiple sclerosis.
A new Harvard study looked at over 35-thousand mothers and daughters.
Researchers found drinking at least 4 glasses of milk a day during pregnancy cut babies' risk of MS in half compared to babies whose mothers didn't drink as much milk.
And it seems vitamin D is key.
Fatty fish like salmon and sunlight exposure are other major sources of vitamin D.