NYON, SWITZERLAND — The estimated average vitamin D requirement is 800 to 1,000 International Units (I.U.s) per day for older adults in a position statement issued May 10 by the International Osteoporosis Foundation. The requirement is above the 600 I.U. currently recommended for people over age 70 by the Institute of Medicine.

According to the I.O.F., based in Nyon, vitamin D intakes may need to increase to as much as 2,000 I.U. per day for people who are obese, have osteoporosis, are limited in their exposure to sunlight, or have malabsorption, which is faulty absorption of nutrients from the intestines. The objective of the I.O.F. statement was published in Osteoporosis International.

“Global vitamin D status shows widespread insufficiency and deficiency,” said Bess Dawson-Hughes, lead author and a professor at Tufts University in Boston. “This high prevalence of suboptimal levels raises the possibility that many falls and fractures can be prevented with vitamin D supplementation. This is a relatively easy public health measure that could have significant positive effects on the incidence of osteoporotic fractures.”

The Food and Nutrition Board of the Institute of Medicine in 1997 recommended daily Adequate Intake (A.I.) levels of vitamin D of 200 I.U. for people age 0-50, 400 I.U. for people age 51-70 and 600 I.U. for people over age 70. An Institute of Medicine committee has been analyzing A.I. levels for vitamin D and calcium and is expected to issue new A.I. level recommendations this year.