It can be found in some animal-based foods in its pre-made form, or found in plants in the form of beta-carotene -- a compound your body digests to form two vitamin A molecules. Yellow and dark green vegetables and fruits are good sources of the carotenes, including beta-carotene.
With the flu, you may feel very weak and fatigued for up to two or three weeks. You'll have muscle aches and periods of chills and sweats as fever comes and goes. You may also have a stuffy or runny nose, headache, and sore throat.
How long does the flu last? As harsh as the flu can be, the good news is that most people feel much better within one to two weeks. Most healthy adults become contagious the day before symptoms develop (which makes it trickier to prevent from spreading). They remain infectious for up to five to seven days after symptoms appear.