Capsules should keep oils save from rancidity
Q. I read in your column about the tendency of oils to go rancid. Now I notice that my bottle of fish-oil gel capsules says the bottle should be kept tightly closed. Up until now, I've been putting my day's or even week's pill allotments into a small, open container. Sounds like this might be a problem. How long do you think fish-oil capsules can be exposed to the environment and still be effective and safe?
-- N.R., e-mail
A. Air and the oxygen it contains can react with, or oxidize, oils, and by doing so negate their beneficial qualities. The part of the oil that is most susceptible is a point of unsaturation, which makes a polyunsaturated oil, such as fish oil, especially vulnerable. Oils destroyed in this way are said to have gone rancid, and there is a particularly unpleasant smell to provide the unmistakable evidence.
Gel capsules come in various types and qualities and are designed to provide a barrier to protect their contents. Over time, there can be some gaseous interchange, but for all practical purposes, they will do the job. It is important to keep them out of the light -- especially sunlight, and away from any source of heat. I would stick with brands that use quality-control dating. You'll see a "best if used by" or a "use by" date stated clearly on the package.
Some products might use manufacturers' codes, and this can be a set of numbers and/or letters. If you prefer this product, you can always contact the manufacturer to decipher the code and get the expiration date equivalent.
Q. Your response to a question about osteoporosis and Vitamin D has me concerned. Im a 70-year-young female with osteopenia. For the past 10 years, I have been taking Fosamax. You stated in your article, adequate intake of vitamin D for seniors age 51 to 70 is 400 IU per day, but take care not to overdo it. My endocrinologist has me taking an additional 2,800 IU per week with my weekly Fosamax. Fortunately, my bone loss is stable, and Im in relatively good health. I look forward to your comment on the conflicting Vitamin D recommendations.
-- M.M., Bridgewater, N.J.
A. The recommended daily value for vitamin D is 400 IU per day, and newer data would indicate that higher intakes of vitamin D are not only safe, but they may offer some advantages not only for osteoporosis and osteopenia (often a forerunner to osteoporosis), but for other health issues, as well. I was too conservative with my caution about the upper limits for Vitamin D. Here is some recent information.
The June 2007 issue of the American Journal of Clinical Nutrition looked at the intake of vitamin D and calcium, and the risk of all cancers over a four-year period in healthy postmenopausal women over age 55. The study reported that women taking 1,400 to 1,500 milligrams of calcium per day had a 47 percent lower incidence of cancer when compared with those taking a placebo.
Of interest is the fact that those taking 1,100 IU per day of vitamin D along with the calcium had a 60 percent lower incidence of cancer. When the analysis looked only at cancers diagnosed after the first 12 months, the group taking vitamin D plus calcium had a 77 percent lower incidence of all cancers. The cancer incidence did not change with the calcium-only group.
A study in the October 2006 issue Journal of the American College of Nutrition reported that about two-thirds of a rural population of postmenopausal women fell below the blood level considered to be the lower end of the optimal range. In this group, it would take a daily supplement of 2,000 IU of vitamin D to bring them up to the desired level.
Finally, a study in the January 2007 issue of the American Journal of Clinical Nutrition reviewed existing evidence and recommended a change in the safe upper limit for vitamin D, currently set at 2,000 IU per day by the Food and Nutrition Board.
The studys authors recommended that the safe upper limit be raised to 10,000 IU per day. The paper was written by the Council for Responsible Nutrition, a Washington-based trade association representing the dietary supplement industry, so it is unclear whether the upper limit will be changed.
The reason I cite this last study is to let you know that mounting evidence favors a liberalization in the thinking about upper limits for vitamin D. Be assured that your physician-recommended intake is within a reasonable range. My apologies if I alarmed you unnecessarily.
All this being said, some people are hypersensitive to vitamin D. Likewise, anyone considering higher levels of this nutrient should be certain to mention this to his or her health professional, as there can be interactions with prescribed medications and certain health conditions.
For more information about vitamin D, visit http://tinyurl.com/dfy38. A Web site that discusses implications regarding new discoveries for this nutrient can be found at http://tinyurl.com/2oleh8.