Archive for the ‘Vitamins and Minerals’ Category

Sodium and Iodine intake

Friday, May 27th, 2011

You can get iodine from salt and from food

My wife subscribes to a healthy cooking magazine and I sometimes read parts. Last week I was puzzled by their piece regarding appropriate dietary sodium intake. There were three column, one for younger adult women, one for "older" women (starting at 51) and one for all adult men.

The levels were 2,300 mg per day for young women and all men and 1,500 mg a day for men. Yet sodium recommendations (in various publications) for older adults of both genders as well as African Americans of any adult age, and those of us with high blood pressure, diabetes or kidney disease (a total of perhaps 70% of our total population) range from 1,300 to 1,500 mg per day . The American Heart Association now recommends all of us limit our sodium intake to 1,500 mg/day.  http://circ.ahajournals.org/cgi/content/full/123/10/1138.

I decided to write an email to the magazine and mentioned that they were behind the power curve. I got a prompt answer from their senior dietitian; in their June edition they'll be listing a lower figure for older men. I thought. 'It's a start, at least."

Then I received the June 2011 edition of the Harvard Heart Letter. One question that arises when we're told to cut back on salt, is will we stinting on iodine? The title of the lead article gave a direct answer: "Cut salt--it won't affect your iodine intake." The subtitle continued in the same theme: "Iodized salt provides only a small fraction of daily iodine intake."

Those of us over the age of 19 should get 150 micrograms of iodine per day (The senior vitamin/mineral supplement we take contains 150 micrograms/tablet). The recommendations are higher for women who are pregnant or breast-feeding (220 and 290 micrograms respectively).

We also get iodine from dairy products including cheese and yogurt, eggs, marine fish and vegetables that come from regions where the soil contains lots of iodine. Essentially all iodine ingested in food and liquids is absorbed and bio-available (This is not true for iodine in thyroid hormones taken for therapeutic purposes). So I searched to see if we might be getting too much iodine. The data is vague, but an old World Health Organization recommendation I found stated that 1,000 micrograms/day was felt to be safe.

Thyroid check in pregnant woman

We need iodine to enable our thyroid glands to synthesize thyroid hormone. Too little iodine intake leads to hypothyroidism and enlargement of the thyroid gland (goiter). That's bad enough for adults, but worse for fetuses, infants and children where too little iodine can seriously affect brain development.

Most Americans, especially those who eat lots of processed food, take in excess sodium. But the majority of the food-producing companies in adding salt to their products, don't use iodized salt.

You can get all your needed iodine from the AHA-recommended sodium intake (NB. not all salt is iodized) and from "natural" foods Processed foods just add sodium you don't need.

But if you're pregnant (or might be), ask your own doctor.

 

 

Posted in additives, Healthy eating, medically-oriented background info, Publications, Vitamins and Minerals | No Comments »

grass-fed (and grass-finished) vs. grain-finished beef

Wednesday, April 20th, 2011

What's your beef?

We've been buying meat (a bison we split four ways, a young sheep we shared with another couple and, most recent a quarter beef) that's been grass-fed and grass-finished. I always thought it was a healthier way to eat red meat, even though overall we're eating smaller meat portions, more fish and chicken, lots more fruit and veggies all the time and an occasional meat-free main meal.

Now I found a very well done (no pun intended) examination of the issue at the CNN.com website. CNN discussed the Cooking Light Test Kitchen. We have a subscription to that magazine and enjoy its recipes, but I didn't know much about its test kitchen. They had a complete article on the grass-finished vs. grain finished beef controversy. I say grass-finished since essentially all cows eat grass to start with, but some eat only grass and perhaps some hay for six months to a year. Others, those who end up in those huge feedlots like the ones we see when we drive east in Colorado, eat corn mixed with soy and other edibles and are given hormones and lots of antibiotics, whether they are ill or not.

I won't even get into the subject of drug-resistent bacteria in this post, but instead I'll stick to the question of "Can a grass-finished ruminant taste good and can I afford to buy grass-finished beef?" I should mention bison as well, but that meat wasn't tested in CNN's study.

In short, the answer is going to be yes for almost all of us. I know the meat will be less fatty (there's always going to be some fat, of course), but cooked properly, anyone other than those who are specially "trained to evaluate sensory characteristics in beef" won't know the difference. I have a friend who raised beef cattle in Nebraska and disagrees with me on the subject, but the Nutrition Journal article I just quoted (I printed the entire journal article that was mentioned in passing in the CNN piece), basically said it's what you grew up eating. Consumer "sensory panels", that represent the vast majority of us, they felt, were more of an art than a science.

So what are the advanatges and disadvantages of grass-finished beef. It's got fewer calories, roughly four and a half pounds worth per year if you eat as much beef as the average American. Its fat is yellower than the grass-finished cow's, representing more beta-carotene, a significant antioxidant. And it contains more omega-3s as well as more Vitamin A & E.

Disadvantages? It may cost more, if you buy it at the supermarket, but try your area's CSA or look for a local farmer who raises beef and buy it in bulk. CNN got 243 pounds of meat for $5.32 per pound, just a tad higher than they would have paid in supermarkets. We paid <$3 per pound for the quarter cow we bought recently. I'll finish the Chico State article + one from Tufts in another post.

Posted in food and food-producing animals, Healthy eating, medically-oriented background info, Publications, Vitamins and Minerals | No Comments »

Focus on Vitamin B-12 again

Tuesday, January 18th, 2011

high-dose B-12

I've been reading a number of articles about Vitamin B-12 lately. One convinced me we should be taking a higher dose at our age. In young people B-12 deficiency is rare; that's not true for the elderly where some have estimated up to 15% may be lacking in this essential nutrient. What I hadn't fully realized is the omeprazole (Prilosec) I take chronically could potentially also block absorption of B-12.

B-12 deficiency, when severe, causes macrocytic anemia, low red blood cell counts with the cells themselves being larger than normal. That's the flip side of iron-deficiency anemia where the cells are smaller than usual. But there are a host of other issues attributed to B-12 deficiency: depression, dementia, confusion, appetite loss, balance problems. All those have many other causes, of course.

We had been taking a multivitamin for seniors, but added high-dose B-12, (1500 mcg/day. Like the rest of the B vitamins, B-12 is water soluble and if one takes "too much' it can be excreted in urine. That's not true for fat-soluble vitamins like Vitamin D where the potential for overdose is worth thinking about (although there is ongoing debate as to how much Vitamin D we should be getting; see my last post). Our senior vitamin mixture has 25 mcg of B-12 or about 4 times the recommended daily (RDV) value for young healthy adults, but I don't care if I take more than that since I'm about to turn 70 and take that proton pump blocker omeprazole.

beef liver

Today the Wall Street Journal in its Health and Wellness section had an article about B-12 deficiency. It is more likely to be seen in people who don't eat meat or dairy products (beef liver has 48 mcg/slice which is 800% of the RDV). Several chronic bowel diseases  (e.g., celiac disease) can lower its absorption.

The Institute of Medicine recommends that anyone in their 50s or older get most of their intake of this essential vitamin from supplements or, alternatively from so-called "fortified" cereals. When I looked at the NIH's lists of foods that contain larger amounts of B-12, I was somewhat surprised to see at least eight cereals listed.

There is a blood test for B-12 with normal levels of 200-800 picograms per milliliter  cited as the normal range. But my own doc just said my level was superb, ~1,000 pcg/ml in January of 2009. There are now B-12 nasal sprays and some people with severe deficiency have to get B-12 shots, but she talked to a hospital pharmacist who said, just tell me to take my Prilosec at a different time of the day than my B-12.

So if you are 70+ or have a chronic bowel disease or are a vegan, you may want to ask your physician about a B-12 level.

Posted in medically-oriented background info, supplements, Vitamins and Minerals | No Comments »