Posted: April 15, 2020
By Kathryn Ciamaichelo, Morrison Living Nutrition Care Manager
The benefits of Vitamin D, often called the ‘sunshine’ vitamin, have been gaining attention over the last few years. Several studies have suggested that Vitamin D’s role in health goes far beyond just bone health. Vitamin D may help inflammation, depression, immunity, and cellular growth – which can affect a range of diseases including cancer, diabetes, cardiovascular disease, autoimmune diseases, as well as brain diseases like Parkinson’s and Alzheimer’s. There is also a strong correlation between higher serum (blood) levels of Vitamin D and a decrease in falls and fractures in the elderly.
Vitamin D synthesizes in the skin when exposed to sunlight. Through a complex process, the UVB rays stimulate the skin, liver, and kidneys to produce the active form of Vitamin D3, which occurs naturally in animal-sourced foods such as salmon, herring, cod liver oil, while Vitamin D2 is plant-based and is used to fortify milks, orange juice, and cereals.
For adults over the age of 70, the Institute of Medicine (IOM) recommends blood levels of greater than 50 nmol/L (nanomoles per liter). Blood levels below that threshold may be considered insufficient and increase risk for bone-related diseases such as osteomalacia or osteoporosis. Some estimates show that 50% of older adults have insufficient or deficient levels of Vitamin D. This can be due to several factors.
As we age, our skin loses its effectiveness at synthesizing Vitamin D and we likely spend less time outdoors. People living at certain latitudes as well as people with darkly pigmented skin, will have less production of Vitamin D. Some medications may also decrease vitamin D levels.
Vitamin D supplements is often recommended for adults over the age of 65, especially those with limited exposure to the sun or who live at latitudes above 33 degrees north or below 33 degrees south and/or have limited dietary intakes. Both Vitamin D2 and D3 supplements have proven to be effective at raising blood levels of Vitamin D, however, D3 appears to be more potent when given at higher doses. The RDI, or Recommended Dietary Intake, for adults 70+ years, is 800IUs/day.
Both the Geriatric Society and the IOM consider a daily intake of up to 4000IUs safe. For some individuals, a monthly supplement may be preferred over a daily supplement.
If you think you might be deficient in Vitamin D or benefit from a supplement, talk with your doctor. The blood test is quick and simple and can help guide them in making the best recommendations for you.