Take Vitamin D

You may want to take vitamin D supplement if you use sunscreens and avoid the sun.  At least 15 minutes per day of direct sunlight (UVB) is needed for optimum Vitamin D production.    Sunscreen inhibits the production of vitamin D, and you could develop a vitamin D deficiency.  Vitamin D is important for prevention of rickets and osteoporosis and some cancers, including melanoma. Vitamin D is crucial to help the body absorb calcium for good bone health. People with darker skin are at higher risk for deficiencies from sun protection than those with whiter skin. The darker your skin, the more you need vitamin D. Many dermatologists find many of their patients have vitamin D levels below the normal range. [Sunscreen]

Take 200% of recommended daily allowance or 800 IU.

If you don't get any sun, Dermatology Times recommends taking  a daily supplement of  800 IU of vitamin D to keep a mature adult in good bone health and eliminate the need for sun exposure. 800 IU corresponds to 200% of the recommended daily allowance of Vitamin D.  [DermatologyTimes] 

How to get enough vitamin D:  

15 minutes of direct sunlight is needed for normal Vitamin D production. If you can't tolerate the sun at all, then you should take a vitamin D supplement to get the recommended daily allowance of 800 IU for sun sensitive people. Vitamin D is stored in the body for up to two weeks. The darker your skin, the more you need vitamin D. The following is a list of sources where you can get vitamin D. Read your vitamin  and other supplement bottles to see how much vitamin D they contain.

• Daily multivitamin: 400 IU (from my daily vitamin bottle)
• Vitamin D supplement: 800 IU (from my vitamin D bottle)
• Calcium supplement: 200 IU  (from my calcium bottle)
• Vitamin D is also  in a few foods such as  fortified dairy products and fish.
• Vitamin D can be toxic in high doses, so don't take too much.
• Ten to fifteen minutes of sun exposure at least two times per week to the face, arms, hands, or back without sunscreen is usually sufficient to provide adequate vitamin D between hours of 10 and 4 pm.  [Dietary Supplement Fact Sheet Vitamin D]

References for more information on Vitamin D:

http://lpi.oregonstate.edu/infocenter/vitamins/vitaminD/