I just dropped DD off at nursery. It's 12 degrees and sunny with clouds. DD has very sallow skin and I would never have put sun cream on her on a day like today. I used to be deficient in vitamin D myself and know that it's important to be exposed to a degree of sunlight.
Nursery have just pulled me up for dropping her off without suncream on.
I should add that I have provided a bottle of suncream to the nursery which they apply as & when required so if today was to get much warmer, they have her suncream there.