Too Many Elderly Lacking in Vitamin D

From the WebMD Archives

May 16, 2001 -- Chronically ill elderly patients who are home bound or confined to nursing homes appear to be at great risk for vitamin D deficiencies, even if they receive the recommended daily levels of the vitamin in supplement form, a new study finds.

The authors suggest that many elderly patients who are bedridden or in wheelchairs may actually be suffering from muscle weakness caused by severe, but easily treatable, vitamin D deficiencies. The findings were reported at the annual meeting of the American Association of Clinical Endocrinologists, held earlier this month in San Antonio.

"Vitamin D deficiency should be suspected in an elderly patient who has muscle weakness and is wheelchair-bound or bed-bound," researcher Rajesh Garg, MD, tells WebMD. "Unfortunately, most doctors don't test for this or think of it as a problem. But if a patient is deficient, treating them with vitamin D can have dramatic results."

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Vitamin D is important in building and maintaining bone strength, and also acts as a hormone to regulate the growth and development of other tissues. In children, severe deficiencies can cause the bone-deforming condition known as rickets, and in adults it can lead to soft and broken bones. For most people, exposure to sunlight provides most of the vitamin D that is needed, but people who do not go outside or live in areas where there is not much sun may be at increased risk for vitamin D deficiencies.

Garg and colleagues measured vitamin D levels in 18 elderly patients who were either nursing home residents or home-bound due to illness. They found that 16 of them had low to low-normal levels of the vitamin, even though most of the patients were taking supplemental multivitamins with the recommended daily allowance of vitamin D of 400 IU.

The researcher suggests that even twice that amount may not be enough in chronically ill and even healthy older patients, because absorption of the vitamin tends to be impaired with age.

"I would suspect that even among the healthy elderly population, vitamin D levels would not be normal," Garg says. "I also think that many younger people who do not get much sun are deficient, but we don't know this because it has not been studied." Garg is currently a resident at New York's Wyckoff Heights Medical Center.

Endocrinologist Jeffrey Mechanick, MD, who also studies vitamin D deficiency, agrees that older patients may need more than 800 IU of supplemental vitamin D each day, but he warned that no one should take high doses of the vitamin unless they first clear it with their doctor.

"Routinely taking more than 800 IU without consulting a doctor could be very dangerous, especially if a person is also self-medicating with calcium supplementation," Mechanick says. "That could lead to hypercalcemia, or excessively high levels of calcium in the blood, which could be life threatening."

Mechanick, who is an associate clinical professor of medicine at New York's Mount Sinai School of Medicine, says the hypothesis that treating vitamin D deficiencies may help bedridden or wheelchair-bound elderly people become more mobile is intriguing, but needs much more study.

Last year Garg and colleagues reported the cases of five wheelchair-bound patients in Buffalo, N.Y. -- three of whom were elderly -- who were suffering from severe muscle weakness caused by a lack of vitamin D. When the five patients were treated with megadoses of the vitamin, all were able to walk again. It was this study, Garg says, that led him to examine vitamin D deficiencies in the elderly.

"You can't draw conclusions from anecdotal data, which is what this study was," Mechanick says. "These findings indicate that vitamin D is a magic bullet, and that is not very likely. One might hypothesize, from what we do know, that vitamin D could make a patient stronger. But before we jump to conclusions we need to study this further."