Obviously be careful when getting your vitamin D in the sun because a sun burn can deplete your body of many micro nutrients and minerals.
Another great thing about the body and mind is association. We often associate sunshine with warmth, summer, and summer foods, like citrus and fresh herbs.
This association can be very useful when using aromatherapy for moods. Using citrus essential oils and herb oils can often uplift your spirits and brighten your mood.
You can try some pre-mixed blends such as Citrus Bliss by DoTerra or a single oil that you like or blend your own.
Here are a few that I like to diffuse, especially as I'm looking forward to the season and those smells are not quite naturally in the house yet.
3 drops Wild Orange oil
1-2 drops Peppermint oil
3 drops each Lemon and Lavender oil
5 drops Lemon oil
1 drop Coriander oil
3-5 drops Grapefruit oil
1-2 drops Peppermint oil optional
Citrus oils are also great for cleaning and make your house smell great at the same time!