Vitamin D deficiency

Although the body can create vitamin D, there are many reasons deficiency can occur. For instance, darker skin color and the use of sunscreen reduce the body's ability to absorb the ultraviolet radiation B (UVB) rays from the sun needed to produce vitamin D.

A sunscreen with sun protection factor (SPF) 30 can reduce the body's ability to synthesize the vitamin by 95 percent. To start vitamin D production, the skin has to be directly exposed to sunlight, not covered by clothing.

People who live in northern latitudes or areas of high pollution, work at night and stay home during the day, or are homebound should aim to consume extra vitamin D from food sources whenever possible. Infants who are exclusively breast-fed need a vitamin D supplement, especially if they are dark-skinned or have minimal sun exposure. The American Academy of Pediatrics recommends that all breastfed infants receive 400 IU per day of an oral vitamin D supplement; drops made specifically for babies are available.

Although vitamin D supplements can be taken, it is best to obtain any vitamin or mineral through natural sources wherever possible.

Symptoms of vitamin D deficiency
Symptoms of vitamin D deficiency may include:

Getting sick or infected more often.
Fatigue.
Painful bones and back.
Depressed mood.
Impaired wound healing.
Hair loss.
Muscle pain.
If Vitamin D deficiency continues for long periods of time it can result in:

• obesity
• diabetes
• hypertension
• depression
• fibromyalgia
• chronic fatigue syndrome
• osteoporosis
• neurodegenerative diseases, such as Alzheimer's disease

Vitamin D deficiency may also contribute to the development of certain cancers, especially breast, prostate, and colon cancers. We explain this in a little more detail later.
Vitamin D food sources

Sunlight is the most common and efficient source of vitamin D. The richest food sources of vitamin D are fish oil and fatty fish. Here is a list of foods with good levels of vitamin D:

• cod liver oil, 1 tablespoon: 1,360 IU
• herring, fresh, raw, 4 ounces: 1,056 IU
• swordfish, cooked, 4 ounces: 941 IU
• raw maitake mushrooms, 1 cup: 786 IU
• salmon, sockeye, cooked, 4 ounces: 596 IU
• sardines, canned, 4 ounces: 336 IU
• fortified skim milk, 1 cup: 120 IU
• tuna, canned in water, drained, 3 ounces: 68 IU
• egg, chicken, whole large: 44 IU