Vitamin D is a fat-soluble vitamin that is naturally present in very few foods, added to others, and available as a dietary supplement. It is also produced naturally when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis.
Vitamin D is essential for promoting calcium absorption in the gut. Without sufficient vitamin D, bones can become thin, brittle, or misshapen. It is also needed for bone growth in children and helps protect older adults from osteoporosis.
Vitamin D has other roles in human health, including strengthening of neuromuscular and immune function and reduction of inflammation.
Chronic vitamin D deficiency symptoms can include: muscle weakness, aches and pains.
Shocking Vitamin D deficiency statistics
- 32 percent of doctors and med school students are vitamin D deficient.
- 40 percent of the U.S. population is vitamin D deficient.
- 42 percent of African American women of childbearing age are deficient in vitamin D.
- 48 percent of young girls (9-11 years old) are vitamin D deficient.
- Up to 60 percent of all hospital patients are vitamin D deficient.
- 76 percent of pregnant mothers are severely vitamin D deficient.
- Up to 80 percent of nursing home patients are vitamin D deficient.
The flesh of fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources. Small amounts of vitamin D are found in beef liver, cheese, and egg yolks.
Fortified foods provide most of the vitamin D in the American diet. Examples are fortified milk, cereals, some brands of orange juice, and yogurt.
Most people meet their vitamin D needs through exposure to sunlight.
Approximately five to 30 minutes of sun exposure between 10 a.m. and 3 p.m. at least twice a week to the face, arms, legs, or back without sunscreen usually lead to sufficient vitamin D synthesis.
Individuals with limited sun exposure, such as persons living in colder climates or places that don’t see much sun light, need to include good sources of vitamin D in their diet or take a supplement.
In supplements and fortified foods, vitamin D is available in two forms, Vitamin D2 and Vitamin D3. Vitamin D3 could be more than three times as effective as vitamin D2. Many supplements are being reformulated to contain vitamin D3 instead of vitamin D2.
Obtaining sufficient vitamin D from natural food sources alone can be difficult. For many people, consuming vitamin D-fortified foods and being exposed to sunlight are essential for maintaining a healthy vitamin D status. In some groups, dietary supplements might be required to meet the daily need for vitamin D.
Consult a professional
Ask your doctor if you can have simple blood test which would show if you are vitamin D deficient. Remember, before taking vitamin D or increasing your sun exposure ask your doctor if it is right for you.
References: Office of Dietary Supplements, National Institutes of Health (2008), Naturalnews.com, Vitamin D myths, facts, and statistics January 1, 2005 By: Mike Adams.
Nasca is a public health nurse and a “The Hillsider” board member