Finding Vit D Level low in your test results is quite common and one should maintain his or her Vit D Level as 30 I.U. as per standard measuring parameter. It can be corrected by taking weekly sachet or tablet of 60k power Vit D on empty stomach early in the morning as people same way as people having hypothyroid condition take their thyroid medicines. Vit D is essential for strong bones as well as excellent immune response system. In cases of depression associated by low Vit D Level, it has been observed that after correcting Vit D deficiency, the depression may get corrected and the person become normal.
Calcium and Vit D both form essential bone tissue and calcium should also be taken while on Vit D treatment. It can be taken on daily basis for few weeks.
After 12 weeks it is better to check the levels again and stop the medication if there is desired levels found after the treatment. Please remember that unnecessary and prolonged vit D and calcium may damage one's liver and kidneys. So never take excessive treatment.
Exposure to early morning sunlight or evening sunlight at sunset time induce natural synthesis of vit d in one's body. The exposure should be on sufficient area of one's skin like upper and lower limbs for 2-3 minutes time. That much is sufficient. The scorching sunlight won't be helpful for vit D synthesis, rather it may cause tanning.