News Release Distributed 03/25/11
The Institute of Medicine recently announced new recommended intakes for vitamin D, according to LSU AgCenter nutritionist Beth Reames.
Vitamin D, often called the “sunshine vitamin,” helps the body absorb and use calcium to build strong bones and teeth and maintain muscle strength. The new recommended intake for North Americans is 600 International Units (IUs) of vitamin D per day, Reames says. People age 71 and older may need more – as much as 800 IUs per day.
The Institute of Medicine sets national nutrient standards and has set the new Recommended Dietary Allowances somewhat higher than the previous values for some age groups.
“Studies show that the vitamin D levels in many older adults are below recommended levels,” she said. “Together with calcium, vitamin D helps protect older adults from osteoporosis.”
Without sufficient vitamin D, bones can become thin, brittle or misshapen. Vitamin D also plays a role in maintaining the body’s immune function and reducing inflammation.
“Recent research suggests that a lack of vitamin D may also play a role in increasing risk of certain types of cancer, diabetes, cardiovascular disease, autoimmune disease and obesity,” Reames says. “But results have been mixed and inconclusive.”
Most people can meet their needs for vitamin D by eating foods with vitamin D. Good food sources include vitamin D-fortified milk and orange juice, fortified breakfast cereals and fatty fish such as salmon, mackerel, tuna and sardines as well as fish oils, especially cod liver oil.
The institute’s report advises against routine use of high-dose supplements because of concerns about adverse health effects.
“The report states that many people are over-supplementing with vitamin D,” Reames says. “Because vitamin D is a fat-soluble vitamin and is stored in the body, it can potentially become toxic at high levels.”
The body makes vitamin D when skin is exposed to sunlight's UV rays, and many people meet their vitamin D needs through exposure to sunlight. One recommendation to meet vitamin D needs is to get approximately five minutes 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.
“Increasing age and having dark skin decrease the body’s ability to make vitamin D from sun exposure,” Reames says. “Vitamin D production at 70 years old is only 30 percent of what it was at age 25.”
A blood test is used to determine vitamin D deficiency.
Rick Bogren