Rickets used to be a fairly common childhood disease due to vitamin-D deficiency and lack of sunlight exposure. It led to bone deformity, including bowed legs that are seen in some older people today.
Fortifying milk and other foods with vitamin D, along with increased public health awareness, greatly reduced the incidence of rickets but vitamin-D deficiency remains a problem — especially in the elderly. Lack of vitamin D affects bone metabolism leading to osteoporosis, muscle weakness and increased risk of fracture. Conversely, proper amounts of vitamin D may decrease the risk of cancer, cardiovascular disease and infection.
Vitamin-D deficiency is very common in older adults. For the last two years, I have been checking vitamin D levels in my patients and more than half have some degree of insufficiency and many are severely deficient. I am struck by how often patients who appear relatively healthy and seem to eat a balanced diet are affected.
One problem is that older people often don’t eat the same foods as when they were younger. Fortified milk, margarine, cereal and eggs, which are great sources of vitamin D for young people, are often missing from my older patients’ diets. The best natural dietary sources of vitamin D come from fresh salmon (preferably wild caught) but canned fish, including salmon, tuna, mackerel and sardines, are also rich in vitamin D. Dried shitake mushrooms are another great source but are usually not staples of most diets.
Exposure to sunlight increases skin synthesis of vitamin D. A sensible amount of sun exposure to the arms and legs would be five to 30 minutes at least three days per week. That’s enough to get the benefit while avoiding skin damage from too much exposure.
Because many of my patients’ diets are deficient in vitamin D, I recommend a vitamin D supplement often in combination with calcium. For most people, 800 to 1000 units per day from supplements and dietary sources will suffice. For those with severe deficiency, I order a prescription dose of vitamin D for several months along with a supplement to be continued indefinitely.
If you think you may be vitamin-D deficient — many older people are — check with your doctor about getting a blood test or start taking a supplement and spend a little more time outdoors in the sun. Don’t forget your sunscreen!
Dr. James Davis is a board-certified geriatrician with the UCLA Geriatrics Program, which has offices in Westwood and Santa Monica. Information: 310.206.8272 or 319.4371.