In the northern latitudes, we normally get all the vitamin D we need from the sun in the summer. This time of year and throughout the winter, vitamin D from the sun becomes problematic and we must look for alternate sources:

The National Osteoporosis Foundation recommends 400 - 800 IU of vitamin D daily for adults younger than 50, and 800 - 1000 IU for adults to fight disease.

1.   Eat naturally vitamin D-rich foods. Eat oily fish such as salmon (360 IU), sardines (250 IU) and tuna (200 IU) a few times a week.

2.   Fortified foods. Look for vitamin D in milk, orange juice, other fruit juices (100 IU), soy milk (120 IU), butter substitutes (80 IU), and some cereals and yogurts.

3.   Take a supplement. Add a calcium and vitamin D supplements containing at least 400 IU of vitamin D daily. (Most multivitamins contain this much, and many calcium-vitamin D supplements contain 1,000 IU per capsule.)  Men are cautioned in taking calcium supplements due to the increased risk of prostrate cancer.

4.   Enjoy "a little" safe sun - 15 minutes on your hands, a few times each week.
Our bodies produce their own vitamin D through exposure to the sunlight - and fortunately, all you need is about 15 minutes on your hands, a few times each week. Every time sunlight warms our skin, our body produces vitamin D. However, sunlight is unreliable and several factors influence its ability to induce vitamin D production, including: the angle of the sun, the latitude in which you live, your skin pigmentation, age, and use of skin-care products containing sun-protection factor (SPF). Also, there's the not-small matter of skin cancer risk, which is heightened by exposure to sunlight.

Source: Health Magazine