It begins with fatigue and aching bones. Soon the pain in the bones become severe. Extreme muscles weakness sets in. If the condition is left untreated, the patient becomes bedridden, with tiny fractures all through the body.

Bones that were once strong, bracing structures like the steel girders of a skyscraper now resemble the ancient wooden beams of an old, ready-to-collapse building.

The condition: Osteomalacia, also know as adult rickets. The cause: not enough vitamin D. While calcium prevents the roof from crashing in, your bones need Vitamin D to properly absorb that mineral. You get D free of charge from sunlight and from foods like herring, mackerel, sardines, salmon, tuna, swordfish and shrimp. Fish-liver oils are also high in the vitamin. And the best way to get vitamin D and calcium together is from milk.

Until recently most doctors thought that a vitamin D deficiency was rare in adults. Unfortunately, that’s not so. Some elderly people don’t drink milk, eat fish, take codliver oil or get much sun. So they get little vitamin D. Their bodies still get calcium, however – by stealing it from their very skeletons. The result is pain and broken bones.

“As many as 30 to 40 percent of all hip fracture patients in the U.S have osteomalacia,” estimates Samuel H. Doppelt, M.D., of Harvard Medical School. Uriel S. Barzel, M.D., professor of Medicine at Albert Einstein Medical College in New York City feels that the condition is much more common than was generally believed and “that it should be routinely considered in all older patients with vague complaints of pain and weakness.”

Dr. Barzel treats his osteomalacia patients with a regimen of 1,500 milligrams a day of calcium, plus large amounts of Vitamin D (the Recommended Dietary Allowance is 400 I.U. of vitamin D a day. Always check with your doctor for vitamin overdose. Within two weeks of starting these treatments, his patients feel stronger. After a few months, their bones are back up to snuff, the pain is gone, and the Vitamin D supplementation is reduced to 400 I.U a day to prevent vitamin overdose.