Vitamin D Crucial to Bone Health
Reported November 9, 2005
(Ivanhoe Newswire) — It takes both calcium and vitamin D to make healthy bones. Now, researchers from Iceland suggest vitamin D may be more important than doctors thought.
The study reveals it takes adequate vitamin D status to maintain proper levels of a hormone responsible for managing calcium levels in the blood.
Researchers studied about 2,300 healthy adults in Iceland who filled out food questionnaires to measure calcium and vitamin D intake. The participants were divided into three groups based on age then further divided based on calcium intake and a measurement of vitamin D in blood samples.
Researchers also measured levels of the parathyroid hormone (PTH), which is known to play a role in maintaining proper blood levels of calcium and phosphate and is generally thought to increase when vitamin D or calcium intake is insufficient.
The study results illustrate how people with sufficient vitamin D status were more likely to have ideal levels of PTH even when they took in less than 800 milligrams of calcium per day. Conversely, higher calcium intake in the presence of insufficient vitamin D intake was not enough to ensure proper levels of PTH.
The authors conclude, “Our study suggests that vitamin D sufficiency may be more important than high calcium intake in maintaining desired values of PTH.” They believe most people living in northern climates where sun exposure is lower should receive vitamin D supplementation.
SOURCE: The Journal of the American Medical Association, 2005;294:2336-2341
