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.
Flu symptoms will often start quickly. You can start to feel sick about 1 to 7 days after you come in contact with the virus. Most of the time symptoms appear within 2 to 3 days. The flu spreads easily. It can affect a large group of people in a very short amount of time. For example, students and co-workers get sick within 2 or 3 weeks of the flu's arrival in a school or workplace.