Most people get some vitamin D from sunlight; however, people who live in the northern part of the United States make less vitamin D than those in the south, especially during the winter months when the sun is lower in the sky, temperatures are colder and everyone is bundled up when they go outside.
Vitamin D deficiency is associated with bone loss and muscle weakness, which can lead to fractures and a significant loss of quality of life. Low blood levels of vitamin D are also linked to cardiovascular disease, obesity, dementia in older adults, asthma in children, cancer, diabetes and multiple sclerosis.
Aside from exposure to sunlight, vitamin D can be found naturally in fish, fish oils, egg yolks, cheese, fortified milk and beef liver; however, none of these sources can fulfill your daily requirements. The recommended daily allowance for vitamin D is 600 international units per day for children and teens and adults up to 70 years older. Those over the age of 70 should increase their intake to 800 IUs per day.
As with everything, too much of a good thing can be bad for you. Though extremely rare, vitamin D toxicity causes nausea, mood changes and can lead to organ damage. It is recommended that adults get no more than 4,000 IUs per day from food and supplemental sources. Before beginning vitamin D supplementation, it's a good idea to talk with your primary care doctor to determine if screening for low vitamin D levels with a simple blood test is warranted and to make sure the dose and supplement are right for you.
For more information on how to manage vitamin D deficiency, visit mountnittany.org.
Article originally posted in the March 2012 issue of State College Magazine.