Along with a lunch break you also need a sunshine break, really. Vitamin D is needed to help your body absorb calcium for bone growth.
People with darker skin need to be outside longer than fairer skinned people to get the same amount of vitamin D due to the amount of melanin they have.
We all need to be outside longer to get that vitamin D this time of year.
According to Science Daily Spanish researchers say you should spend at least 10 to 20 minutes outside during the summer and spring - but nearly 2 hours during the winter and fall.