Vitamin D and Healthy Aging

The Introduction

vitamin DWe have known for many years that a deficiency of vitamin D has been linked to osteoporosis and bone fractures in older people. However, recent research has also linked Vitamin D insufficiency with higher incidences of many medical conditions that affect the risk of death, including hypertension, diabetes, cardiovascular disease, cancer, and infection. Research has shown that older people do not take in enough vitamin D in their diet, despite them knowing they need to. Moreover, older adults are at high risk for vitamin D insufficiency because of a lower ultraviolet (UV) B light exposure from lower levels of outdoor activity, especially in winter months and especially in colder climates. This study examined the relationships between a blood pre-cursor of vitamin D (serum 25-hydroxyvitamin – [25(OH)D)] levels) and mortality (death) in a representative U.S. sample of older adults over the age of 65 years.

The Research

3,408 community-living Americans were followed over a seven-year period. They had their blood levels of 25-hydroxyvitamin levels measured and their cardiovascular disease risk factors (blood pressure, blood fats, diabetes) and death rates observed over the period.

The Results

The study showed that older adults with insufficient intake of vitamin D die from heart disease at a greater rate than those with adequate intakes. The research showed that those with the lowest blood levels of 25-hydroxyvitamin had the greatest risk of death and those with the highest levels the lowest risk of death. The American research team concluded that the current dosage recommendations for vitamin D supplementation appear to be inadequate in most older adults to support these higher 25(OH)D levels that are associated with optimal general health and reduced mortality.

The So What?

This research highlights the need for older people to ensure adequate intakes of vitamin D to elevate and maintain blood levels of 25(OH)D. Skin exposure to the sun on a daily basis is the major means by which vitamin D is created within the body. Thus, skin exposure to the sun is crucial to ensure this occurs as is an adequate dietary intake of vitamin D. Thus, people at risk are those who cover their body too much, have dark skin, shiftworkers and those who have limited exposure to the sun. It is recommended that during winter we get 2-3 hours of sun exposure per week and in summer, 5-15 minutes twice a day. Great dietary sources of vitamin D include cod liver oil, salmon, tuna and mackerel, mushrooms, egg yolk and dairy products.  Vitamin D needs of masters athletes are discussed at length in chapter 16 of The Masters Athlete.

Ginde, A., Scragg, R., Schwartz, R., and Camargo Jr., C. (2009). Prospective study of serum 25-hydroxyvitamin D level, cardiovascular disease mortality, and all-cause mortality in older U.S. adults. Journal of the American Geriatrics Society, 57(9): 1595-1603.