The Vitamin D and Calcium Debate: How Much Is Enough?

We all know vitamin D and calcium are two very important nutrients. Most of us readily admit to supplementing with both. Yet there seems to be a great deal of discrepancy around how much we need. The recommended dietary allowance (RDA) for adults and children are different, as are RDAs for men, women, and seniors. If you’re turning to the web to double check how much vitamin D or calcium you should be getting, here’s some words of caution from two recent studies.

One study set out to evaluate Canadian and U.S. coverage of the Institute of Medicine (IOM)’s report, “Dietary Reference Intakes for Calcium and Vitamin D.” This report attempted to accurately determine the amount of calcium and vitamin D needed to produce beneficial health effects in the body but also to establish an upper limit for which negative effects start to appear. In other words, they wanted to know how much is enough and how much is too much.

After publishing their report, many high-circulation newspapers in both Canada and the U.S. covered the recommendations of the IOM. A research team then compared the content of the articles. They were looking for differences in those written by reporters who had already published vitamin D related articles prior to the IOM response and compared them to articles written by reporters without this history.

The research team found that the news articles which cited the key findings of the IOM report were reported inconsistently. Many articles simply didn’t report the IOM recommendations at all. Most articles tended to ignore the issue of vitamin D overconsumption.

What were the recommendations of the IOM?

• Adequate intake of vitamin D for men and women up to the age of 70 was set at 600 IU

• Adults over the age of 70 should be getting 800 IU of vitamin D

• The maximum amount of vitamin D for adults was raised to 4,000 IU

• In terms of bone health, a serum concentration of 50 nmol/l (20 ng/ml) is adequate for 97% of the population

As for calcium, here are the IOM recommendations:

• 1,200 milligrams of calcium per day for women 51 and older.

• 1,200 milligrams of calcium per day for men aged 50 to 70

• The safe upper limit of calcium is set at 2,000 to 3,000 mg per day for adults.

Some experts will dispute these numbers. One team of researchers was able to show that the recommended level of vitamin D as stated by the IOM isn’t high enough to reduce the incidence of fracture or falls. What’s more, when blood levels of vitamin D were higher than the IOM’s recommendations, the researchers noted positive benefits in the bone densities of both young and older adults. This, they say, suggests that the IOM upper limit is too low for optimal bone health.

In contrast, they feel that the IOM upper limit for calcium is too high. The say that high calcium intake can cause adverse effects for the heart, as well as difficulties with kidney stones.

It sounds like vitamin D and calcium supplementation is still an issue of contention amongst medical researchers. Talk to you doctor about supplementing with either of these two nutrients in order to establish an effective dose for your health needs.

Source(s) for Today’s Article:

Bischoff-Ferrari, H., et al., “Comment on the IOM Vitamin D and Calcium Recommendations,” Harvard School of Public Health web site; http://www.hsph.harvard.edu/nutritionsource/vitamin-d-fracture-prevention/, last accessed August 8, 2013.

Hatfield, D.P., et al., “Critical assessment of high-circulation print newspaper coverage of the Institute of Medicine report Dietary Reference Intakes for Calcium and Vitamin D,” Public Health Nutr. August 2013; 1: 1-9.