Vitamin D: New Findings About Deficiency And Dose
Dr. Robert Heaney is one of the leading researchers in the quickly-advancing field of vitamin D research. He recently gave a fascinating lecture at UC Berkley in which he summed up the most current information about vitamin D with respect to what have been difficult-to-answer questions about vitamin D deficiency and dose. Dr. Heaney’s information is compelling and commands a complete rethink of this crucial prohormone nutrient. The video has since been removed from YouTube, but we were able to see it and took some notes. Here’s what this leading researcher had to say about vitamin D.
It’s a shame this video was removed because it really brings the viewer up-to-date on vitamin D, using recent research to address what have been the most difficult and clinically-compelling questions about vitamin D.
- What constitutes a vitamin D deficiency?
- What’s likely to happen when you don’t get enough?
- How should doctor’s test for vitamin D status?
- How much should people take?
- How toxic is it and at what level?
- What form is best?
Dr. Heaney starts out by disavowing any financial interest in vitamin D although jokingly (but accurately) points out that there isn’t much financial interest in vitamin D to begin with. That’s certainly true when you look at the cost of vitamin D supplements.
After defining terms like deficiency and sufficiency, Heaney uses vitamin D to make a good case for how and why physicians need to rethink the current concepts of nutrient deficiency diseases. In particular, doctors need to stop looking at nutrient deficiencies as either/or propositions. Heaney also suggests we do away with blurry distinctions between “deficiency” and “insufficiency”. Instead, we should recognize that there are optimal levels for each nutrient, and then there’s everything below that. Heaney states that sub-optimal levels of nutrients can and do play a role in any disease process.
In terms of what should constitute a “deficiency” in a medical sense, Heaney points out that long before a frank deficiency disease is present, sub-optimal levels of any nutrient can adversely affect health in many ways. It’s already known, for example, the amount of folic acid needed to prevent its associated deficiency disease is much less than the amount a woman needs to prevent neural tube defects.
Dr. Heaney presents some startling data on just how prevalent sub-optimal vitamin D levels are across wide-swaths of population, and nearing 100% is some critical populations like hospitalized patients.
With this data, Dr. Heaney seems to be suggesting that rather than trying to define a deficiency state, doctors and researchers should be refining the processes by which they test, evaluate and then correct the status of each nutrient.
Vitamin D is actually a prohormone and when converted to its active form in the body (1,25-dihydroxy vitamin D) it regulates several different processes. Heaney traces the main pathways of D in the body and shows how suboptimal levels lead to disorders of calcium and phosphate metabolism or (osteoporosis) or immune function (cancer) and hypertension.
Dr. Heaney went on to explain the best way for physicians to test for vitamin D status (total D levels) and interpret test results. He also emphasized that the rate at which individuals convert vitamin D supplements into biologically active D is highly variable.
What type of vitamin D is best? Using his own data, Heaney showed that vitamin D 3 (cholecalciferol) produced far superior results to vitamin D 2 (ergocalciferol) in terms of raising and sustaining actual blood levels of active D, but also that D 2 could be used to treat vitamin D deficiency just as easily as vitamin D 3. Note: Vitamin D 2 is a vegetarian source, D3 is always from an animal source, either lanolin or fish liver oil.
In terms of toxicity, Dr. Heaney showed that toxicity is extremely low. So low, in fact that it’s hard to put a precise number on what constitutes a toxic dose. Although he emphasizes that he’s not advocating sky high doses, Heaney suggests that, at a minimum, you’d need to be taking around 30, 000 IU a day for a long period of time before toxicity would become an issue.
Heaney has stated that a healthy man metabolizes 3-5 1000 IU of vitamin D per day.
In terms of a general recommendations, Dr. Heaney’s data show that for most people, a minimum of 2600 IU of vitamin D 3 per day is needed to maintain ideal levels of biologically active vitamin D in the body.
Since you’re not going to find a 2600 IU vitamin D supplement, and since toxicity is virtually a non-issue, you can take slightly more or less than that amount by using almost any vitamin D supplement, taking multiple softgels if necessary, which are always very small and easy-to-swallow.
It’s almost unfortunate that vitamin D has such a low profit potential, because it guarantees that no matter how compelling a case research can make for the importance of D supplements, there’s never going to be a high profile ad campaign to publicize the crucial and indispensable role it plays in protecting health throughout life.