If you suffer from anxiety or panic attacks, you should read the following and then assure that your blood-vitamin D levels are optimal. Your 25(OH)D, or calcidiol, level should be between 50-60 ng/ml.
Anxiety is pandemic in the USA, and according to a 2007 research study, vitamin D deficiency correlates very closely to anxiety in people who suffer from fibromyalgia. Also, two studies of mice with abnormal vitamin D receptors in the brain found an increase in anxiety, aggression, poor grooming, maternal pup neglect and cannibalism. 
Though more research is needed before drawing definitive conclusions, it is likely that vitamin D plays a part in this disorder. I discussed in an earlier blog the evidence for vitamin D deficiency as a cause of brain and nervous-system disorders, and anxiety fits that category. The mice studies just cited also make one wonder if the horrible increase in both paternal and maternal child abuse is not due in part to the fact that the American Academy of Dermatology and others of the “sunscare” industry have done such a good job in frightening people out of the sunlight, thereby creating our critical, widespread vitamin D deficiency—food for thought.
 Armstrong, D. et al. Vitamin D deficiency is associated with anxiety and depression in fibromyalgia. Clin Rheumatol. 2007;2):551-4.
 Kalueff, A. et al. Increased anxiety in mice lacking vitamin D receptor gene. Neuroreport 2004;15:1271-74.
 Kalueff, A. et al. Behavioral anomalies in mice evoked by Tokyo disruption of the vitamin D receptor gene. Neurosci Res 2006;54:254-60.