Have 400 IU of Vit D daily for healthy bones

Eat dairy products, orange juice, soya milk, and cereals everyday, as a study finds that Recommended Dietary Allowance (RDA) for vitamin D should be 400 International Units (IU) for healthy bones.

The results of the study were presented at ENDO 2017, the annual scientific meeting of the Endocrine Society, in Orlando, Florida.

"The RDA is easily achievable with a supplement of 400 IU in winter, when vitamin D levels are lowest in North America," said principal investigator J. Christopher Gallagher from the University School of Medicine in Omaha, US.

"This has important ramifications for public health recommendations. The amount of vitamin D needed, 400 IU daily, is less than the figure recommended by Institute of Medicine," Gallagher added.

By estimating the RDA for vitamin D intake, the laboratory method used for measuring serum 25-hydroxyvitamin D, 25(OH)D, can affect the results," he said.

"The estimated RDA based on the older immunoassay (DiaSorin S.p.A., Salugia, Italy) system was 800 IU daily, whereas the newer liquid chromatography tandem-mass spectrometry (LC-MS/MS) technique estimated that 400 IU daily would meet the RDA."

The participants were randomized to one of seven vitamin D3 doses: 400, 800, 1600, 2400, 3200, 4000, 4800 IU/day or placebo, for 1 year, and all the women were given calcium supplements to maintain a total calcium intake.

After analysing the samples and estimating the RDA using the older immunoassay, the authors reported that 800 IU daily would meet the vitamin D intake requirement for 97.5 percent of the population.

"Remember, this RDA is for bone health only," Gallagher cautioned. "It may be different for other diseases. Although trials looking into cancer, diabetes, and other diseases are ongoing, we do not have information about this yet.