Absorption after WLS

April 15, 2003

Got a question.....

Has anyone found any research concerning absorption of nutrients from foods

after WLS.... My doctors say I don't malabsorb as much as I think I do (165

cm bypassed), and that the intestine tends to " learn " to absorb what the

bypassed portion doesn't, over a period of time. Hmmmm... I wonder how true

this is.... I'm wondering about this since myself and a few other's here are

bodybuilding now.... I need lot's of nutrients, lots of protein and lot's

other foods just to maintain my weight and muscle tissue..... All the

fitness mags have great info on eating and bodybuilding, but, how much

applies to us? Any info would be great..... Please post to the group (if

you're a grad..lol.. If not then private will work) since other's here are

wondering about this also.....

Thanks in advance,

Randy

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Beyond Change excerpts

Smaller doses taken more often, whether in food or supplementation, are more

effective than one large dose, as only 10-30% is absorbed at one time. Loose

powder, liquid, or quick dissolving tabs usually allow for greater

absorption. (what about chewables?) Chelated minerals are better absorbed

than non-chelated. (Sally Myers)

Low carb eating plan info and support: www.lowcarbluxury.com

from Part I (July 2002)

" Nutrient deficiencies following bariatric surgical procedures can lead to

serious health consequences if left unattended. The provision of knowledge to

bariatric surgical candidates of the nutrient deficiencies associated with

their particular surgical procedure and the steps necessary to avoid their

occurrence is the responsibility of the bariatric surgeon and his/her staff.

Taking those steps, however, is solely the responsibility of the patient.

Do you take your vitamin/mineral supplements on a daily basis and in the

amounts recommended? Is your body losing bone because you can't remember to

take your calcium? Does your body feel tired and run down because you refuse

to take iron? Is your hair falling out and are your muscles diminishing in

size because you eat too little protein or refuse to use protein supplements?

Do you realize that hair loss, reduced muscle and bone are only a few of the

many health consequences of long-term nutrient deficiencies? That anemia is

likely to develop with deficits in iron, B12, and folate intake or

absorption? And, did you know that without sufficient levels of zinc, defects

in immune function may occur?

Are you aware that low intake or absorption of B-vitamins can lead to

neurological defects and damage, some of which are irreversible

(untreatable)? Do you know that low anti-oxidant vitamin and minerals may

increase the risk for cancer, heart disease, diabetes, hypertension,

cataracts, other diseases, as well as promote aging? "

(balance of article omitted; does not deal with gastric bypass procedures)

from Part II (August 2002)

" Gastric bypass combines both gastric restriction and malabsorption to induce

massive and sustained weight loss. With (this) procedure, the part of the

stomach that produces acid and digestive enzymes is bypassed and the newly

formed small gastric pouch produces negligible amounts of acid and digestive

enzymes. Without stomach acid and digestive enzymes, certain foods are not

adequately broken down to release their nutrient content.

The pouch also produces no intrinsic factor, an agent that must bind to

vitamin B12 for its absorption from the gut into the body. The bypass

procedure, therefore, causes deficiencies in vitamin B12, the vitamin that

assists in the metabolism of food, DNA replication and repair, nerve

conductance and function, the formation of blood cells, and more.

Bypass of the duodenum causes malabsorption of, and therefore deficiencies in

iron, calcium, zinc, and folate. Other B-complex vitamins are also reduced

with gastric bypass, both as a result of decreased absorption and to reduced

nutrient intake and digestion. Further more, the bypass reduces fat

absorption which may consequently cause deficiencies of fat-soluble vitamins,

including D, E, K, and A.

Studies have shown that daily multivitamin and mineral supplements, at

amounts close to the RDA, correct most micronutrient deficiencies following

surgery, with the exception of zinc, calcium, iron, folate, and vitamin B12.

These vitamins and minerals generally require supplementation at amounts

greater than the RDA.

Several studies have found that, even with supplementation, iron deficiencies

occur in 30-50% of the gastric bypass population, and are more common among

pre-menopausal women (than in males and post-menopausal women). Within the

first two years following surgery, 30-40% of gastric bypass patients have

been reported to suffer from anemia secondary to poor iron absorption.

Iron deficiencies can be treated or prevented with iron taken at amounts

given to women during pregnancy - 40mg. Iron as fumerate or chelated to amino

acids are the most readily absorbable forms of supplemental iron. And heme

iron, obtained from eating meat, is far more readily absorbed by the gut than

is non-heme iron from plants or supplemental sources.

Approximately 20% of the gastric bypass population is likely to develop

folate deficiencies. Such deficiencies can be corrected or prevented by

intake of supplemental folate at 800-1000 micrograms per day or approximately

200% of the RDA.

Vitamin B12 deficiencies occur in as many as 40-50% of patients, even while

on supplements that meet the B12 RDA. As mentioned above, the small gastric

pouch does not produce intrinsic factor necessary to bind B12 for its

absorption out of the gut and into the body.

Studies have found that B12 deficiencies, for the majority of gastric bypass

patients, can be prevented or effectively treated with B12 supplements in

amounts that are high enough to cause passive diffusion of B12 across the gut

in the absence of intrinsic factor. B12 supplemented at amounts far in excess

of the RDA (as high as 100-350 micrograms) have been found to prevent B12

deficiencies in more than 95% of post-surgical gastric bypass patients.

Sublingual B12 (under the tongue) taken daily may also be effective in the

prevention of B12 deficiencies since the vitamin is absorbed into the

bloodstream and does not need to bind to intrinsic factor for absorption. B12

shots taken daily or monthly are also effective in bypassing impaired B12

absorption and in preventing and treating B12 deficits.

Defects in folate and B12 may cause pernicious anemia as well as elevated

production of homocysteine and concomitant increased risk of cardiovascular

disease. Symptoms of folate deficiency include weakness, headache,

palpitations, forgetfulness, hostility, irritability, paranoid behavior,

apathy, sore tongue, gastrointestinal tract disturbances, and diarrhea.

B12 deficiencies may also cause gastrointestinal disorders, such as diarrhea,

cramping, constipation, as well as palpitations, shortness of breath, and

extreme fatigue. Neurological deficits secondary to B12 deficiencies include

impaired bladder control, numbness, tingling of the extremities, moodiness,

agitation, disorientation, insomnia, confusion, dimmed vision and even

delusions and hallucinations. Some of these neurological deficits caused by

B12 deficiencies may be irreversible.

Calcium deficiencies occur following gastric bypass for several reasons.

First, the duodenum, where calcium is actively absorbed, is bypassed.

Secondly, there is insufficient acid produced by the pouch to provide enough

acid in the gut for appropriate calcium absorption. Third, changes made in

the mixing of food with pancreatic juices may alter vitamin D absorption. And

finally, some patients become lactose intolerant after surgery and avoid

dairy products.

Low calcium is known to cause bone loss. Recent studies have also found that

low calcium intake is associated with weight gain. Calcium supplements may

prevent bone loss and also assist in promoting weight loss and preventing

weight regain following bariatric surgery.

Calcium supplements of 1200-1500mg, taken in 400-500mg aliquots 3 times per

day are recommended for individuals who have had gastric bypass surgery.

Calcium citrate, rather than calcium carbonate, is more readily absorbed in

the non-acidic environment of the gut. Absorption is further enhanced by

calcium supplements that include vitamin D and magnesium.

The high risk for B12, folate, iron deficiencies following bypass surgery

requires that the individual have periodic tests (annually) for blood levels

of ferritin (iron), folate, and B12. Blood tests for measurement of calcium

are unreliable. When blood calcium is low, the body " borrows' calcium from

bone and teeth, so that levels may appear normal. Thus it is wise for the

gastric bypass patient to have a bone scan, a bone demineralization test, or

some other test than can be used as a marker for low calcium.

Protein deficiencies are common and occur secondary to 1) low calorie intake,

2) avoidance of meat, 3) negligible acid and digestive enzymes produced by

the stomach, and 4) reduced absorption of protein by the bypassed gut. Low

protein intake can cause muscle loss which, in turn, leads to a reduction in

basal metabolic rate, interfering with maximal weight loss success. The heart

is also a muscle and can lose tissue with severe protein deficiencies. For

these reasons, protein supplements and high intake of protein is encouraged

for all gastric bypass patients --and for life. "

(balance of article omitted; deals with BPD/DS rather than gastric bypass)

Author: Buffington, Ph.D., director of research for the Bariatric

Centers for Weight Loss Surgery in Ft. Lauderdale.

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from Carol A

(I have more stuff but no time to dig it all out right now)

April 15, 2003