Hello. I am a 25 year old female. I just got my bloodwork done and it says I have slight hypothyroidism, I'm low on testosterone for a female, and my Vitamin D level is ridiculously low. It was measured at 13. What I don't understand is, I am outside ALL the time. I am big into the outdoors. I have light skin, hazel eyes, and live in Arkansas. I've had this deficiency before and I lived in Kansas, but was still a huge outdoor enthusiast. I don't understand why it's so bad. Help?