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Low grade fever
with body ache
is a common presentation of a viral infection, even without any other symptoms as you mentioned . Make sure that you consume good amount of fluids daily and I understand though your appetite will come down , you could try eating small bites frequently and keep your body well fed. This treats half the infection.
See to it that your temperature does not go up and you could take Tab PARACETOMOL three times a day , after meals .If you do not feel better in 3 days , I suggest you to visit the local Doctor . You can continue your vitamins
and fish oil.
Wishing you a speedy recovery