Late last year The Institute of Medicine released its recommendations on Vitamin D blood levels and new DRI levels. Their very conservative approach was challenged at the time by Dr. Robert Heaney, of Creighton University in Omaha, Neb. one of the foremost Vitamin D researchers in the United States. Heaney said at the time that the IOM had chosen to ignore a great deal of research to come up with their new recommendations, which raised the DRI from 400 IU/day for adults to 600 IU/day, and set target blood serum levels of 20ng/L.
Heaney went into depth on that research at a session Thursday at Nutracon, New Hope Natural Media’s conference connected with SupplyExpo and Natural Products Expo West 2011 in Anaheim, Calif. He made a convincing case that the IOM was way off base.
“To say that 20ng/L is adequate for bone health, well, you simply can’t support it,” Heaney said.
Heaney summed up more than 40 studies on the effect of vitamin D on bone health, fracture risk, etc. The overwhelming majority showed strong support for shooting for a 32ng/L as a minimum level for healthy bones. Heaney went into detail showing vitamin D’s role in the body’s “calcium economy,” i.e. the movement of calcium in and out of the skeleton.
But Heaney also likened the vitamin D picture to an iceberg, with the calcium economy piece being the just the tip. The 85 percent of this berg below the water line represents the function of vitamin D within cells.
Cells manufacture their own form of D as part of a response to various stimuli, Heaney said. Vitamin D functions as the key that unlocks the DNA molecule, which is now understood to be active almost all the time, Heaney said, not just during cell division. As the intracellular vitamin D unlocks the DNA, the cell is able to manufacture new forms of cellular equipment that would enable it to respond appropriately to being touched by a tuberculosis bacterium, to use one example. While the cells manufacture this form of D themselves, they can’t do so efficiently enough without an appropriately high blood serum level of D.
“The endocrine pathway of vitamin D (the tip of the iceberg) has been known for many years,” Heaney said. “The autocrine pathway has been known only for about 5 years.
The research delving into the autocrine pathway has opened up a whole new universe for vitamin D research. Heaney cited a long list of diseases and conditions with strong research showing adequate vitamin D levels ameliorating these conditions or lessening the risk of developing them.
One of these conditions is high blood pressure, Heaney said. It has been known for years that calcium exerts a small downward modulation on blood pressure, he said. This effect is improved by adding vitamin D. These effects are modest, though, compared with a drug, so physicians usually opt for a prescription, Heaney said, which he views as shortsighted.
“Whatever else you do when treating your patients with high blood pressure, make sure they have enough vitamin D and calcium,” he said.
Heaney summed up his session by linking his research on vitamin D to his wider view of human nutrition. Adequate levels of vitamin D are just one part that must work together others to make a harmonious whole.
“If you pull the flutes out of Beethoven symphony it still sounds like Beethoven, but with something missing. But then pull out the bassoons, and then the horns....”