Very few foods contain Vitamin D. The body synthesizes vitamin D in the skin through exposure to sunlight.
Ask your doctor to take a blood test to determine your levels of vitamin D3. I am not a happy camper with people who take supplements without labs. The test is inexpensive.
Normal levels are 30 or above.
The best thing, if your levels are low, is to take D3 vitamin supplements.
Ask your doctor about how much to take and how often.
Prescription D3 is taken once a week in a dose of 50,000 I.U. Or you may take daily supplements of 1,000 - 3,000 I.U. per day.