Ongoing research is proving that Vitamin D benefits the brain as well as the bones, and may be a significant factor in helping older people stay healthy and vital.

Known as the Sunshine Vitamin because exposure to sunlight can trigger synthesis in the skin, Vitamin D is also available through dairy foods and fatty fish such as halibut and cod.

Vitamin D plays an essential role in the metabolic process, aiding in the absorption of calcium and promoting bone strangth. Without adequate Vitamin D bones can become soft, brittle, or misshapen, and Vitamin D deficiency leads to devastating skeletal diseases like Rickets and osteomalacia.

Research expands the list of vitamin D benefits

The importance of vitamin D’s bone building capability is important to people of all ages, but it’s particularly crucial for older people who have or are at risk of developing osteoporosis. Research has shown that maintaining sufficient vitamin D levels can significantly reduce the risk of this debilitating disease, which is is characterized by bone loss and fragility.

But vitamin D benefits go far beyond strong bones.

* Assists the body’s defense against certain cancers: Ongoing studies of vitamin D indicate that vitamin D may actually help the body protect itself against certain cancers. An increased intake of dairy foods, which are significant sources of vitamin D and calcium, appear to be associated with a lower risk of colon cancer.

* Important to brain health and cognitive ability: a January, 2009 study showed an unmistakable link between low levels of vitamin D and cognitive ability in older people. The study, which was conducted by the the UK’s Cambridge University in conjunction with the University of Michigan, tracked 2000 people aged 65 and older. The results clearly indicated that as vitamin D levels went down, rates of cognitive impairment went up.

* Critical to immune system efficiency: A recent Medical University of South Carolina report says vitamin D functions as a hormone and is crucial to regulating the immune system. The report says long-term vitamin D deficiency has been linked to immune disorders such as multiple sclerosis, rheumatoid arthritis, type I diabetes, and cancer.

* Strongly related to muscle power: A University of Manchester study of adolescent girls showed that participants with sufficient vitamin D levels outperformed those with vitamin D deficiencies on a broad spectrum of tests designed to measure muscle force and power.

* Fights placental infection: A 2008 UCLA study showed that vitamin D induces immune responses in placental tissue by stimulating the production of antimicrobial proteins.

* Crucial for heart health: A number of studies have linked deficiency of vitamin D to heart disease. These studies found rates of severe disease or death may be 30 to 50 percent higher among sun-deprived individuals with heart disease.

People over 50 at greatest risk of vitamin D deficiency

Since the 1930s, when the US government mandated that milk be fortified with vitamin D, the risk of vitamin D deficiency in children has decreased markedly. Now people over the age of 50 are believed to have the greatest risk of developing vitamin D deficiency. As we age the skin’s ability to convert vitamin D to its active form decreases, and older people are more likely to be housebound and get less exposure to sunshine. In addition the kidneys become less efficient at converting dietary sources of vitamin D to its active form.

Caution with supplementation a must

Though supplemental vitamin D may be important for many, it’s essential to use supplements carefully. There are health risks associated with consuming too much vitamin D; taking too much can lead to vitamin D toxicity, which can cause nausea, vomiting, poor appetite, constipation, weakness, and weight loss. It can also raise blood levels of calcium, which can lead to heart rhythm abnormalities, mental confusion, and kidney problems.

The Food and Nutrition Board of the Institute of Medicine considers an intake of 25 mcg (1,000 IU) for infants up to 12 months of age and 50 mcg (2,000 IU) for children, adults, pregnant, and lactating women to be the tolerable upper intake level (UL). A daily intake above the UL increases the risk of adverse health effects and is not advised.