Highway Health: Why We Need Vitamin D

Not only is vitamin D important for the development, growth and maintenance of a healthy body, but recent research has shown that a deficiency in vitamin D is a major factor in the cause of several types of cancer, heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, birth defects, periodontal disease, falls, mortality and a decrease in cognitive functioning.  More than half of the world’s population is at risk of being deficient in vitamin D.  In the U.S. alone, 36% of otherwise healthy young adults have inadequate amounts of Vitamin D and up to 57% of general medicine inpatients have inadequate amounts. African American, Hispanics, and those with higher body mass indexes (BMI) have higher rates of deficiency.

According to The American Journal of Medicine, Vitamin D deficiency is a 25(OH)D concentration, the major circulating form of vitamin D, less than 20 ng/mL.  Insufficiency is at 21-29 ng/mL and greater than 30 ng/mL specifies sufficiency.  It is now recommended that people be screened for deficiency by obtaining a 25(OH)D measurement at least twice/year.

Vitamin D comes in two forms: D₂ and D₃.  Vitamin D₂ is formed in the skin, after being in the sun or being exposed to ultraviolet (UV) radiation.  Vitamin D₃ is also available from animal sources (e.g., cod liver oil, salmon, mackerel, herring) and is in foods fortified with vitamin D (e.g., milk, yogurt, cheeses, various breads and some juice products).  Vitamin D₃ is 2-3 times better at increasing 25(OH)D than the same dose of vitamin D₂.  The American Academy of Dermatology statement on vitamin D states, “that an adequate amount of vitamin D should be obtained from a healthy diet that includes foods naturally rich in vitamin D, foods/beverages fortified with vitamin D, and/or vitamin D supplements; it should not be obtained from unprotected exposure to ultraviolet (UV) radiation”.

Vitamin D and calcium work together and you should therefore strive to get adequate amounts of each daily.  However, it is important to note that too much calcium and vitamin D can have negative consequences. A National Cancer Institute study found a possible increased risk of pancreatic cancer in those with very high vitamin D levels.  Doses above 10,000 IUs/day have been shown to cause kidney damage.  The risk of having kidney stones increases once people exceed 2,000 mgs/day of calcium.  Therefore, aim to follow these guidelines…

Recommended Daily Amounts by Age

Overall, getting the right amount of Vitamin D is essential to staying healthy and leads to several health benefits…

Effects of Vitamin D

*Information taken from The American Journal of Medicine (2009), Vol. 122, No. 9