I am 55 yrs old male. I have persistent low grade Fever on and off for the past one year. .. Fever starts around 9 am and lasts till around 10 pm. It varies from 99 to 99.5 F. I also suffer from asthma since 30 yrs and take preventive medication-seroflo250 rota cap once a day. Six months back I got my D3 level check. It was very low. I took medication to improve my D3. After a few weeks the low grade fever disappeared. I did not have fever for about 7 months. Have again started getting low grade fever since past 1 month. Would be highly obliged if someone could help me . All my tests are clear.