If you check the IRS website, and your return shows 'reviewing', there's really nothing you can do.
Just be patient, and keep checking. TurboTax has no knowledge of why the IRS may be reviewing your return.
You may receive a letter from the IRS telling you why your return is being reviewed, and asking for more information.
The number you can use to call the IRS is 1-800-829-1040. The hours you can call are from 7 AM - 7 PM local time Monday-Friday.
Instructions for the phone selections are as follows:
• Choose your language preference
• Select option 2 for "personal income tax"
• Select 1 for "form, tax history, or payment"
• Select 4 "for all other questions."
• Select 2 "for all other questions." You will then be transferred to an agent.