It's so clear and scientifically appropriate that I'm posting, in full (translation), this brilliant article from the The New York Times, I recommend everyone to read it.
After all, let's reflect: do we really need so many medicines in our lives?
Link to the original post: https://www.nytimes.com/2011/11/29/health/vitamin-b12-deficiency-can-cause-symptoms-that-mimic-aging.html
Ilsa Katz was 85 when her daughter, Vivian Atkins, first noticed that her mother was becoming increasingly confused.
“She couldn't remember names, where she had been or what she had done that day,” Mrs. Atkins recalled in an interview. “At first, I wasn't too worried. I thought it was part of normal ageing. But over time, the confusion and memory problems became more severe and more frequent.”
Her mother couldn't remember the names of close relatives or what day it was. She thought she was going to work or needed to go downtown, something she never did. And she used to get agitated.
An evaluation at a memory clinic resulted in a diagnosis of early-onset Alzheimer's, and Mrs. Katz was prescribed Aricept, which, according to Mrs. Atkins, seemed to have worsened the situation. But the clinic also examined the level of vitamin B12 in Mrs. Katz's blood. The result was well below normal, and the doctor believed that this could be contributing to her symptoms.
They then began weekly injections of B12. “Soon after, she became less agitated, less confused and her memory improved a lot,” said Mrs. Atkins. “I felt like I had my mother back, and she's feeling much better too.”
Now 87, Mrs. Katz still lives alone in Manhattan and feels well enough to refuse outside help.
Even so, her daughter asked herself: “Why aren't B12 levels routinely checked, especially in older people?”
It's an important question. As we get older, our ability to absorb B12 from food decreases, and often so does our consumption of foods rich in this vitamin. B12 deficiency can appear without warning and cause a series of confusing symptoms that have a high chance of being misdiagnosed or attributed solely to ageing.
A Vital Nutrient
Vitamin B12 is an essential nutrient with functions throughout the body. It is necessary for the development and maintenance of a healthy nervous system, the production of DNA and the formation of red blood cells.
A severe B12 deficiency results in anemia, which can be detected by a common blood test. But less obvious symptoms of a B12 deficiency can include muscle weakness, fatigue, tremors, difficulty walking, incontinence, low blood pressure, depression and other mood disorders, as well as cognitive problems such as memory impairment.
Laboratories differ as to what they consider normal, but most authorities state that there is a deficiency when B12 levels in adults fall below 250 picograms per milliliter of blood serum. Like all B vitamins, B12 is water-soluble, but the body stores extra amounts in the liver and other tissues. Even if food sources are inadequate for some time, the deficiency in the blood may not appear for years.
If the amount of B12 stored is already low from the start, the deficiency can develop within a year, or even more quickly in babies.
The recommended dietary amounts of B12 vary: 2.4 micrograms per day for people aged 14 and over, 2.6 micrograms for pregnant women and 2.8 micrograms for breastfeeding women. Unless circumstances impair B12 absorption, these levels are easily achieved with a balanced diet containing animal protein.
In its natural form, vitamin B12 is present in significant quantities only in foods of animal origin, mainly in liver (83 micrograms in a 100 gram portion). Good food sources include other red meats, turkey, fish and seafood. Smaller amounts of the vitamin are found in dairy products, eggs and chicken.
People at risk
Natural plant sources have, at best, minimal amounts of B12, and the vitamin is poorly absorbed from them. Many strict vegetarians and all vegans, as well as the babies they breastfeed, need to consume supplements or fortified breakfast cereals to get adequate amounts.
Certain organisms, such as the bacterium Spirulina and some algae, contain a pseudo-B12 that the body cannot use, but which can generate a false reading of a normal B12 level in blood tests. Despite claims to the contrary, algae such as laver (nori) and barley grass (barley grass) are not reliable sources of B12.
In foods of animal origin, B12 is bound to proteins and needs to be released by gastric acid and an enzyme in order to be absorbed. For this reason, chronic users of medications that reduce stomach acidity, such as Prilosec, Prevacid and Nexium, as well as ulcer medications such as Pepcid and Tagamet, are at risk of developing a B12 deficiency and often need to take daily supplements.
Stomach acid levels decrease with age. Up to 30% of older people may not have enough acid to absorb adequate amounts of B12 from natural sources. For this reason, regular consumption of fortified foods or supplementation with daily doses of 25 to 100 micrograms of B12 is recommended for people over 50.
Synthetic B12, found in supplements and fortified foods, does not depend on stomach acid to be absorbed. However, whether natural or synthetic, only part of the B12 ingested is actually used by the body. Treatment to correct a deficiency usually involves much higher doses than the body actually needs.
Free B12, from both natural and synthetic sources, needs to combine with a substance called intrinsic factor, present in the stomach, in order to be absorbed by the intestine. This factor is absent in people with an autoimmune disease called pernicious anemia; the resulting deficiency of the vitamin is commonly treated with B12 injections.
Although most doctors readily recommend injections to correct the deficiency, there is plenty of evidence that, at sufficiently high doses, sublingual tablets (placed under the tongue) or B12 patches on the skin can work just as well as injections, including in people with absorption problems and even pernicious anemia.
Most of the time, a daily supplement of 2,000 micrograms is recommended for about a month, then reduced to 1,000 micrograms daily for another month and finally reduced again to 1,000 micrograms weekly. Sublingual B12, patches or even B12 lollipops can be useful for those who need the supplement but can't swallow pills.
Other groups at risk of developing B12 deficiency include heavy drinkers (who impair absorption), people who have undergone bariatric or stomach ulcer surgery, and those who take aminosalicylic acid (for inflammatory bowel disease or tuberculosis) or the diabetes drug metformin (sold as Glyphage and other brands). Patients who use anticonvulsants such as phenytoin, phenobarbital or primidone are also at risk.
High doses of folic acid can mask a B12 deficiency and cause permanent neurological damage if normal levels of the vitamin are not maintained. Potassium supplements also impair B12 absorption in some people.
Although B12 deficiency can increase blood levels of the amino acid homocysteine, which is a risk factor for heart disease and stroke, B12 supplementation has not been shown to reduce cardiovascular risk.
And although high levels of homocysteine are associated with Alzheimer's disease and dementia, reducing them with B12 supplements showed no improvement in cognitive function. However, in one study, among women with a low dietary intake of B12, supplementing with the vitamin significantly reduced the rate of cognitive decline.
Translation shared free of charge, without any commercial or profit objective, only with the intention of informing and helping. All rights to the original content belong to The New York Times News Service/Syndicate - All rights reserved.
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