Who's at risk
Vitamin B12 is more difficult to absorb than any other. In order for it to enter the blood, several conditions are necessary in succession: the vitamin must be supplied with food, the stomach must secrete acid and a special protein - internal factor, and the final section of the small intestine must be intact and able to accept it. Failure at any of these stages leads to deficiency, which is why the risk groups are so different - from strict vegetarians to people who have undergone gastric surgery.
- Strict vegetarians and vegans: Vitamin B12 is found almost exclusively in animal foods
- People over 60 years old - with age, stomach acidity and the ability to extract vitamins from food decrease
- Atrophic gastritis and autoimmune damage to the stomach: cells that produce intrinsic factor stop working - this is classic pernicious anemia
- Long-term use of metformin
- Long-term use of drugs that reduce stomach acidity
- Gastric surgery, including resection and bariatric surgery
- Diseases of the small intestine: Crohn's disease, celiac disease, condition after removal of the ileum
- Alcohol abuse
- Breastfed babies if the mother follows a vegan diet
- Previous parasitic infestation of the intestines, in particular infection with broad tapeworm
- Chronic pancreatitis and severe digestive disorders
- Regular use of nitrous oxide, including for non-medical reasons - it destroys the active form of the vitamin
Elderly people deserve special attention. They develop a deficiency even with a nutritious diet with meat and dairy products: with age, the acidity of the stomach decreases, and the vitamin associated with food proteins is simply not released. At the same time, the first manifestations - forgetfulness, unsteadiness, depression - are easily attributed to age, and for years no one has prescribed a simple test.
How it manifests itself
The picture consists of three groups of signs: from the blood, nervous system and digestion. The order of their appearance can be any, and neurological symptoms are quite likely to occur when hemoglobin is still normal.
- Weakness, fatigue, shortness of breath, pallor with a yellowish tint to the skin and sclera
- Burning and soreness of the tongue, it becomes smooth and bright red, taste is dulled
- Numbness, tingling, pins and needles and burning sensation in the feet and hands, usually symmetrically on both sides
- Impaired sense of body position: unsteady gait, poor balance in the dark
- Muscle weakness in the legs, decreased endurance
- A shooting sensation along the spine when the head is tilted forward is a rare but characteristic sign of damage to the pathways
- Memory impairment, absent-mindedness, depression, irritability; in older people it is mistaken for the onset of dementia
- Decreased appetite, heaviness in the abdomen, unstable stools, weight loss
- Premature graying and darkening of the skin on the hands and folds is an uncommon but well-described symptom.
- In children - developmental delay, lethargy, lag in weight gain and loss of already acquired skills
Neurological manifestations usually begin from below and symmetrically: first the feet, then the legs, and later the hands. A person describes this in different ways - “as if I were wearing socks,” “my legs feel like cotton,” “I don’t feel the floor.” Then there is instability when walking, especially in the dark or when the gaze does not help maintain balance: in the shower with eyes closed, in a poorly lit entrance. These signs are not associated with the vitamin and usually go to a neurologist with suspected problems with the spine.
Examination: what is missing in conventional analysis
Diagnostics solves two problems: confirm the deficiency and understand why it arose. The second task is no less important than the first, because it determines whether the treatment will be a course or lifelong.
- Общий анализ крови: эритроциты крупные, их мало, нередко снижены также лейкоциты и тромбоциты.
- Мазок крови: гиперсегментированные нейтрофилы — ранний и очень характерный признак.
- Витамин B12 в сыворотке. Значение в нижней трети нормы дефицит не исключает.
- Гомоцистеин и метилмалоновая кислота — повышаются раньше, чем падает сам витамин, и точнее отражают нехватку в тканях.
- Фолиевая кислота: дефициты часто идут вместе и дают похожую картину крови.
- Ферритин: при сочетании с дефицитом железа эритроциты не будут крупными, и диагноз легко пропустить.
- Антитела к внутреннему фактору и к париетальным клеткам желудка, гастроскопия — поиск причины.
- Тиреотропный гормон: аутоиммунные diseases щитовидной железы часто сопутствуют пернициозной анемии.
- Билирубин и ЛДГ: при выраженном дефиците часть клеток разрушается ещё в костном мозге, и это отражается в биохимии.
- Осмотр невролога с проверкой чувствительности и равновесия — он фиксирует исходное состояние, с которым потом сравнивают результат лечения.
There is also a reverse trap: simultaneous deficiency of iron and B12 is not uncommon, especially after gastric surgery and intestinal diseases. Iron makes red blood cells small, B12 makes red blood cells large, and as a result their average size is completely normal. A general blood test in such a situation looks calm, although there are two deficits at once. That's why it's wise to look at ferritin and B12 together rather than one at a time.
What are the dangers of self-medication with folic acid?
Folic acid and vitamin B12 are responsible for the same stage of blood cell maturation, so if there is a deficiency of either of them, the analysis picture is similar. If you take folic acid if you have a B12 deficiency, anemia will actually decrease: cells will begin to mature normally, hemoglobin will increase, and your health will improve.
- The blood picture with B12 deficiency and with folic acid deficiency looks almost the same
- Folic acid corrects only hematopoiesis and has no effect on nerve fibers
- Anemia goes away, but neurological damage continues to worsen
- The only early signal by which a deficiency could be noticed disappears
- Therefore, if a B12 deficiency is suspected, they first get tested, and only then take anything
But folic acid has no effect on the nervous system. The destruction of the nerve fiber sheaths continues, and the main alarm signal - changes in the blood test - disappears. A person believes that he has been cured, but months later he comes with numbness, weakness in the legs and gait disturbances, which are difficult to recover. This is why multivitamins “for vigor” without tests if B12 deficiency is suspected are unsafe.
Treatment and what to expect from it
Replenishing the vitamin itself is the simple and inexpensive part. The difficulty is different: to correctly determine the duration and not stop in the middle, when your health has already improved, but the cause has not gone away.
- Восполнение витамина инъекционно или в высоких дозах внутрь — форму, схему и длительность определяет врач в зависимости от причины и тяжести.
- Первый ответ виден уже на 5–7-й день: в крови резко растёт число ретикулоцитов, молодых эритроцитов. Это признак того, что лечение работает.
- Гемоглобин обычно нормализуется за 6–8 недель, размер эритроцитов приходит в норму чуть позже.
- Неврологические симптомы уходят медленнее, месяцами, и восстанавливаются тем полнее, чем раньше начато лечение.
- При пернициозной анемии и после операций на желудке или кишечнике терапия пожизненная: причина не устраняется, витамин просто не может усваиваться of пищи.
- Веганам и вегетарианцам нужен постоянный источник витамина и регулярный контроль показателя, а не однократный курс.
Another aspect that is rarely talked about: with autoimmune damage to the stomach, not only the production of internal factor is affected. Such gastritis requires monitoring in itself, since over time it increases the risk of other changes in the mucosa. Therefore, a patient with pernicious anemia is usually recommended not to limit himself to injections, but to undergo gastroscopy every few years - this is part of the diagnosis, and not reinsurance.
How much time do you have left?
The liver stores vitamin B12 for several years, which is both good and bad news. Good - because occasional errors in nutrition are safe. Bad - because a person who has completely eliminated animal food will feel the consequences only after 3-5 years, when the changes have already accumulated.
- Before the onset of anemia, a deficiency can exist for years and not show itself in any way.
- Neurological symptoms lasting less than six months usually go away completely or almost completely
- If the duration lasts more than a year, some violations persist forever
- Therefore, numbness and unsteadiness of gait are not a reason to put off until vacation or until next year.
- After gastric surgery, a deficiency develops faster - reserves are consumed, and supply stops completely
- Children have virtually no supplies, and shortages occur over months, not years.
The practical takeaway for those at risk is simple and inexpensive: get a complete blood count and vitamin B12 level done once a year. This applies to vegans and strict vegetarians, people after surgery on the stomach and intestines, taking metformin and drugs to reduce acidity for a long time, as well as everyone over sixty. Such control is cheaper than any treatment and completely eliminates the main risk - late diagnosis.