Recent evidence has indicated a much higher prevalence of vitamin D deficiency than expected, raising concerns about the potential deleterious effects on health.
Vitamin D deficiency has been linked to bone and muscle problems, as well as a host of other related illnesses including cancer, diabetes, high blood pressure, depression and immune system disorders. In the absence of sun exposure, vitamin D becomes an essential nutrient in the diet. There is particular concern in people over the age of 60 since they get less exposure to the sun and have poor dietary intake of vitamin D.
One simple strategy to prevent these problems and enhance health is to supplement with vitamin D. In an attempt to establish an effective dietary intake of vitamin D to bring blood levels up to acceptable limits, UK researchers performed a dose response study of increasing levels of vitamin D supplementation in men and women older than 64 years.
They concluded that an intake between 316 and 1,712 IUs per day was required to bring the majority of people into a range of preferred vitamin D blood levels.
American Journal of Clinical Nutrition. 2009 May, Vol. 89, No. 5, 1366-74. Epub 2009 Mar 18.