A keto diet is an eating plan focusing on foods that have plenty of healthy fats, sufficient protein and very few carbohydrates. The goal is to gain more calories from the fat than from the carbohydrates.
The diet works by depleting the body of its stores of sugar. As a consequence, fat for energy will start to break down. This results in the development of ketones called molecules which the body uses for fuel. It can also lead to weight loss as the body burns fats.
Many types of keto diet are available, including Standard Ketogenic Diet and Cyclical Ketogenic Diet.
We describe the advantages of the keto diet, as well as its dangers in this article.
Supports weight loss
The ketogenic diet can help to promote weight loss in many ways, including metabolism enhancement and appetite reduction.
Ketogenic diets are foods that fill a person up and that can reduce the hormones that cause hunger. For these reasons, a keto diet can lower the appetite and encourage weight loss.
Researchers found in a 2013 meta-analysis of 13 different randomized controlled trials that people following ketogenic diets lost 2 pounds (lbs) more than those following low-fat diets over 1 year.
Similarly, another review of 11 studies found that, after 6 months, people on a ketogenic diet lost 5 lbs more than those on low-fat diets.
Acne has many common causes and may have ties to diet and blood sugar in certain cases.
Eating a diet high in processed and refined carbohydrates can alter the balance of gut bacteria and cause blood sugar to rise and fall dramatically, both of which can adversely affect skin health.
According to a 2012 report, a ketogenic diet could reduce some people’s acne symptoms by reducing carb intake
May reduce risk of certain cancers
Researchers also explored the ketogenic diet’s role in helping avoid or even cure other cancers.
One research showed that the ketogenic diet could be a safe and effective alternative treatment for use in people with some cancers, alongside chemotherapy and radiation therapy. This is because, in cancer cells, it can cause more oxidative stress than normal cells, causing them to die.
Another recent 2018 study indicates that because the ketogenic diet lowers blood sugar, the risk of insulin complications may also be reduced. Insulin is a blood sugar regulation factor that may have links to certain cancers.
Although some study indicates the ketogenic diet may have some value in treating cancer, studies in this area are minimal. To better appreciate the possible benefits of the ketogenic diet in cancer prevention and care, researchers need to perform further studies.
May improve heart health
It is important that when a person follows the ketogenic diet they choose healthy foods. Eating healthier fats, such as avocados rather than less healthy fats, such as pork rinds, can help boost heart health by reducing cholesterol, some evidence suggests.
A 2017 analysis of animal and human research on a keto diet found that certain individuals reported a substantial decrease in total cholesterol levels, low-density lipoprotein (LDL), or poor cholesterol, and triglycerides, as well as an rise in high-density lipoprotein (HDL), or “healthy” cholesterol.
High cholesterol levels can increase the risk of developing cardiovascular disease. Consequently, reducing the impact of a keto diet on cholesterol will reduce the risk of heart complications in a person.
The review concluded, however, that the positive effects of a diet on heart health depend on the quality of the diet. Hence consuming healthy, nutritionally balanced food is essential when following the keto diet.
May protect brain function
Some research, such as this review in 2019, indicate the ketones produced during the keto diet have neuroprotective benefits, which means they can reinforce and protect the brain and nerve cells.
That is why a keto diet can help a person avoid or control conditions like Alzheimer’s disease.
Further work is, however, required into the effects of a keto diet on the brain.
Potentially reduces seizures
Within a keto diet the combination of fat, protein, and carbs affects the way the body uses energy, resulting within ketosis. Ketosis is a biochemical cycle that the body uses ketone bodies for fuel during.
The Epilepsy Foundation suggests that ketosis in people with epilepsy can reduce seizures — especially those who have not responded to other methods of treatment. More research is needed on how successful this is as it tends to have the greatest impact on children with focal seizures.
A analysis for 2019 supports the theory that a keto diet will benefit people with epilepsy. The ketogenic diet can the symptoms of epilepsy by several different mechanisms.
Improves PCOS symptoms
Polycystic ovary syndrome (PCOS) is a hormonal condition that can lead to excess male hormones, ovulatory dysfunction and ovaries. A high carbohydrate diet can cause adverse effects, such as skin problems and weight gain, in people with PCOS.
Clinical research on ketogenic diet and PCOS are not numerous. One 2005 pilot study investigated five women over 24 weeks. The researchers find multiple PCOS markers improved with a ketogenic diet including:
- weight loss
- hormone balance
- ratios of luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
- levels of fasting insulin
Another 2019 research analysis showed a keto diet has beneficial benefits for people with hormonal disorders including PCOS and type 2 diabetes. Researchers also made aware, however, that the findings were too complex to recommend a keto diet as a general PCOS treatment.
Risks and complications
The ketogenic diet can offer a number of health benefits. However, remaining on a long-term ketogenic diet may have an adverse health effect including an increased risk of the following health problems:
- kidney stones
- excess protein in the blood
- mineral and vitamin deficiencies
- a build up of fat in the liver
The keto diet can cause adverse side effects known to many as keto flu. Those negative effects can include:
These symptoms are especially common at the start of the diet, as the body adjusts to its new source of energy.
Some populations should avoid the keto diet, including:
- people with diabetes who are insulin-dependent
- people who have eating disorders
- those with kidney disease or pancreatitis
- women during pregnancy and breastfeeding
Those who take a type of medication called cotransporter 2 sodium-glucose (SGLT2) inhibitors for form 2 diabetes do not adopt a keto diet either. This medication increases the risk of diabetic ketoacidosis, which is a dangerous condition which increases blood acidity.
It is important to talk to a doctor, dietitian, or trusted healthcare provider about any intended diet plan, especially for people who are trying to manage a health problem or disease.
People who are looking to start the keto diet should seek a doctor’s consultation and check if they have diabetes, hypoglycemia, heart disease, or any other health conditions to ensure a safe eating pattern for the keto diet.
Bear in mind that there is a lack of research on the long term effects of ketogenic diet. It is uncertain if it is more important to sustain the diet for longer periods than less restrictive healthy eating habits.
A ketogenic diet restricts carbohydrates, or significantly limits them. Some carbohydrates do provide health benefits, however. People should eat a diet that contains a range of nutrient-dense, fibrous carbohydrates, such as fruits and vegetables, alongside balanced protein sources, and healthy fats for a less restrictive dietary approach.
How long can I maintain a keto diet safely?
There is a significant amount of research supporting the possible benefits of ketogenic diet, including control of weight loss and blood sugar. However, most research only took place during brief periods of a couple of weeks or months.
Some studies show the advantages of following the ketogenic diet for longer periods of up to 2 years. There is also a shortage of research exploring the possible side effects of adopting a ketogenic diet for prolonged periods of time.
One recent cohort study that tracked 432,179 adults over 25 years correlated large and low intakes of carbohydrates with a higher mortality risk than moderate intakes of carbohydrates. In particular, people who consumed more than 70 per cent or less than 40 per cent of carbohydrate calories were at a higher mortality risk.
While it is likely that if you follow the ketogenic diet correctly on a short-term basis you will lose weight, research suggests that it is probably not the healthiest diet to follow in the long run.
If you want to follow the ketogenic diet, it would be better to limit this dietary trend to a few months, then the transition back to a less restrictive diet that you can maintain for a long time. No matter what diet you are pursuing, remember to make sure you eat whole healthy foods. Jillian Kubala, MS, RD
Answers represent our medical experts’ opinions. All material is purely informational and medical advice should not be considered.
How long does it take for kidney stones to pass?
The kidneys are in charge of filtering the blood for urea and excess minerals. These substances are frequently excreted in the urine. Large concentrations of these minerals can, in some situations, build up in the kidneys, causing crystal-like stones.
Kidney stones can form in one or both kidneys. They may then flow thru the ureter, the tube that links the kidney to the bladder.
Small kidney stones usually pass thru without causing any problems and may not cause any symptoms. Larger stones can become lodged in the ureter and cause pain. They may cause issues such as infection and renal damage if they are not removed.
The speed with which a kidney stone passes can be influenced by a number of factors. More information on how long it takes to pass a kidney stone, how to speed up the process, and treatment options can be found in this article.
When to consult your doctor
Smaller kidney stones may pass on their own, producing little pain. Large stones, on the other hand, can be uncomfortable and raise the risk of health problems.
Pain is a sign that a person needs to see a doctor. They’ll be able to tell if the stone has to be treated in any way to help it pass.
If people have any of the following symptoms, they should see a doctor:
- blood in the urine
- fever and chills
- severe and persistent pain in the back or side
- cloudy or foul-smelling urine
- a burning feeling when urinating
These symptoms could indicate a kidney infection, which needs to be treated right once to avoid more serious problems.
Size and placement are the two key elements that determine how quickly a stone passes.
A kidney stone’s size influences how rapidly it passes through a person’s body. Smaller stones pass more quickly and with less pain.
The approximate timelines for passing kidney stones of various sizes are listed below:
- Around 80% of kidney stones with a size of less than 4 mm will pass on their own in around 31 days.
- Around 60% of kidney stones with a diameter of 4–6 mm will pass on their own after 45 days.
- Around 20% of kidney stones that are larger than 6 mm will pass on their own after a year. When stones are this large, however, it is better to consider surgical removal as soon as possible.
The position of the kidney stone also has an impact on whether or not it can be passed naturally. Some stones develop in the kidney, whereas others develop in the ureter.
Kidney stones that form near the kidney form in the upper section of the ureter. Those that form near the bladder are those that form in the lower section.
According to a 2014 assessment of research, 48 percent of stones that develop near the kidney pass without intervention. For stones that grow close to the bladder, the percentage climbs to 79 percent.
How to speed up the process
Drinking enough of water is the best technique to assist speed up the passing of a kidney stone. The extra fluid increases urine, which aids in the movement of the stone.
A person can also take actions to avoid the formation of new stones and the growth of existing ones. These steps are as follows:
- limiting protein intake
- reducing calcium intake
- consuming less salt
- eating more citrus fruits
Citrus fruits contain the chemical citrate, which can help prevent kidney stones from forming.
Dietitians and doctors can also recommend food programmes for kidney stone management.
Pain relief remedies
Kidney stones can be inconvenient and even painful to pass. In certain circumstances, over-the-counter drugs like ibuprofen may be sufficient to relieve pain.
If a person’s kidney stones are especially painful, they should speak with their doctor, who may be able to prescribe stronger pain relievers.
Treatment and surgery
Kidney stones can be treated without surgery in a number of ways. These are some of them:
- Alpha-blockers: These drugs relax the ureter, alleviating painful spasms and helping the stone pass.
- Calcium channel blockers: These drugs widen the ureter, helping the stone pass through.
- Lithotripsy: This procedure uses sound waves to break the stone into smaller fragments that can pass more easily.
Surgery is rarely the first treatment option. Kidney stones greater than 6 mm, on the other hand, necessitate emergency surgery. Large stones can become lodged in the ureter, resulting in infections and kidney damage.
Ureteroscopy and percutaneous nephrolithotomy are the two main surgical options for kidney stone removal.
A general anaesthesia is required during ureteroscopy. Using tiny instruments introduced via the urethra, the surgeon removes or breaks up the stone during the surgery. A stent may then be placed into the urethra to keep it open. This makes it easier for any little stone shards to flow through.
The surgeon removes very large stones measuring 10 mm or more during percutaneous nephrolithotomy. A tiny incision in the back is used to remove the stone directly from the kidney. The surgery necessitates a general anaesthesia and a one to two-day stay in the hospital.
The time it takes to recuperate from a kidney stone is determined by how quickly it goes. The pain should go away fast if the stone passes naturally or with minimal medication.
If lithotripsy is performed as an outpatient operation, the patient should be able to return home the same day. The amount of time it takes to recover depends in part on the type of anaesthetic used.
If surgery is necessary, most people are able to resume most of their routine activities within a day of the procedure. People who receive a stent, on the other hand, should avoid high-intensity activities until the stent is removed by a medical practitioner. About a week after surgery, something happens.
Pain medicines may be used throughout recuperation.
Kidney stones are often unpleasant, and passing them through the body’s system might take many weeks. If a person’s stones become very painful or if they suffer other concerning symptoms, they should consult a doctor.
Kidney stones can be treated using a variety of methods. The goal of drug therapy is to relieve pain and suffering while also allowing the stone to pass more freely.
Kidney stones that are too large to pass naturally, on the other hand, may need to be surgically removed. Within a day or two of surgery, most people are able to resume their daily activities.
Uses of vitamin B-12 level test: Normal ranges, and results
The amount of vitamin B-12 in the blood or urine is measured in a vitamin B-12 level test to determine the body’s overall vitamin B-12 reserves.
Vitamin B-12 is required for a variety of body functions, including neuron function, DNA and red blood cell formation.
Treatment is required if a person’s vitamin B-12 levels fall outside of the usual range. Vitamin B12 deficiency can cause neurological symptoms as well as fatigue, constipation, and weight loss. B-12 levels that are too high could indicate liver disease, diabetes, or another condition.
Continue reading to learn more about B-12 testing and what the results indicate.
Purpose of a vitamin B-12 level test
The vitamin B-12 level test determines the amount of vitamin B-12 in your body. Doctors can use the data to see if low vitamin B-12 levels are causing symptoms.
If a person exhibits any of the following symptoms, a doctor may recommend a vitamin B-12 level test:
Vitamin B-12 insufficiency
Vitamin B-12 deficiency is thought to affect up to 15% of people in the United States, according to research. The following are signs and symptoms of a deficiency:
- fast heartbeat
- numbness and tingling in the hands and feet
- poor memory
- a sore mouth or tongue
- difficulty maintaining balance
Vitamin B-12 deficiency in infants can cause them to underachieve. They may have mobility issues in addition to developmental delays.
A vitamin B-12 level test may be required for people who have signs of low iron. Pernicious anaemia is caused by a lack of vitamin B-12 absorption, resulting in poor red blood cell causes.
It usually affects the elderly or people who are deficient in intrinsic factor. Intrinsic factor is a gastric material that binds to vitamin B-12 and allows it to be absorbed by the body.
The following are signs and symptoms of pernicious anaemia:
- pale skin
- weight loss
- loss of appetite
High levels of folate in the blood
They can also make you more susceptible to anaemia.
Symptoms of other illnesses
Vitamin B-12 levels that are unusually high can be a symptom of liver disease, diabetes, or certain types of leukaemia. The findings of a vitamin B-12 test may be used by a doctor to help them make a diagnosis.
Vitamin B-12 deficiency is more common in some people than in others, especially those with low stomach acid or other digestive problems. Stomach acid helps the body absorb vitamin B-12 more effectively by separating it from meals.
Low vitamin B-12 levels are more common in the following groups of people than in others:
- people with conditions that reduce vitamin B-12 absorption, including celiac disease and Crohn’s disease
- people who have had gastric bypass surgery
- those who are breast-feeding
- people who are taking medicines such as chloramphenicol, proton pump inhibitors, or H2 blockers
- older adults
- vegans and vegetarians
- people with diabetes
How does the B-12 vitamin level test work?
Vitamin B-12 status is normally determined by a blood test, but home urine tests are now available. Vitamin B-12 levels can be checked as part of a routine blood test by a doctor.
Although fasting is not required before a B-12 test, it may be necessary if the doctor is utilising the test to check at other blood components.
It is important that patients inform their doctors about any medications or supplements they are taking, as some may have an impact on the outcome.
Acknowledging the results
The following are possible results:
- Low. Vitamin B-12 levels below 200 pg/mL are considered low. This indicates that you may have a vitamin B-12 deficiency, pernicious anaemia, or an overactive thyroid. Neurological symptoms are common in people who have low vitamin B-12 levels.
- High. Anything over 900 pg/mL is considered excessively high vitamin B-12 status. This result could indicate problems with the liver or kidneys, diabetes, or certain types of leukaemia.
Because the ranges of results differ from one laboratory to the next, it’s important to talk to a doctor about the results and what they signify.
To rule out vitamin B-12 deficiency, the doctor may measure levels of methylmalonic acid (MMA) and other chemicals. These lab results aid in the early detection of vitamin B-12 deficiency.
Vitamin B-12 deficiency treatment
Vitamin B-12 injections are frequently required by people who have low amounts of the vitamin. These shots are more successful at boosting vitamin B-12 levels than supplements, especially when people have medical issues that make supplements difficult to absorb.
High doses of vitamin B-12 supplements may help some people improve their B-12 status. Supplements are sold in the form of capsules or liquids in pharmacies, supermarkets, health food stores. It may also be beneficial to consume extra vitamin B-12-rich foods.
Treatment for high vitamin B-12 levels
There is no upper limit on vitamin B-12 consumption because high amounts do not cause problems. Having naturally high levels of vitamin B-12 in the body, on the other hand, could be cause for alarm, since it could indicate a serious underlying condition. Doctors will focus on treating the underlying medical condition rather than the vitamin B-12 levels.
Vitamin B-12 foods.
Although low vitamin B-12 levels are frequently caused by absorption problems and other medical conditions, some people may be deficient because they do not acquire enough vitamin B-12 through their food. This is especially true for vegans and vegetarians who have been vegetarian for a long time.
Vitamin B-12-rich foods include:
- fortified plant-based dairy alternatives
- fortified breakfast cereals
- fortified nutritional yeast
- fish and seafood
- dairy products
Vitamin supplements can help vegans and strict vegetarians make up for dietary deficiencies. Older persons should seek to achieve their vitamin B-12 needs through fortified meals and vitamin supplements, as supplements are simpler for their bodies to absorb than naturally occurring vitamin B-12.
Vitamin B-12 dietary recommendations
Vitamin B-12 is required in 2.4 micrograms (mcg) per day for adults and adolescents over the age of 14. During pregnancy, this rises to 2.6 mcg, and breast-feeding raises it to 2.8 mcg.
Vitamin B-12 is an essential nutrient that is necessary for good health. The status of a person’s vitamin B-12 is determined by a vitamin B-12 level test. This test may be recommended by a doctor to people who have symptoms of a deficiency or who are at risk of having low vitamin B-12 levels in their bodies.
Vitamin B-12 deficiency can be avoided by eating a well-balanced diet that includes many sources of the vitamin on a daily basis, or by taking supplements. If they have trouble absorbing vitamin B-12 from food, oral supplements or injections can help them avoid symptoms and consequences.
Uses, benefits, and side effects of vitamin B-12 shots
Vitamin B12 shots are injections that a doctor may recommend to address a nutrient B12 deficiency, particularly if the body has trouble absorbing the vitamin.
A doctor may recommend oral vitamin B12 supplementation or injections if a person’s vitamin B12 levels are low owing to a medical condition.
Injections are typically used by people who have difficulty absorbing vitamin B12 or who have had stomach surgery. Shots allow the body to absorb vitamin B12 without having to pass it thru the digestive system.
The necessity of maintaining proper vitamin B12 levels is discussed in this article, as well as the benefits and risks of vitamin B12 shots.
Vitamin B12 is a water-soluble vitamin that is important for a variety of biological activities, including:
- nerve cells
- red blood cells
- DNA production
Megaloblastic anaemia can make a person feel fatigued and weak if they don’t get enough vitamin B12.
Vitamin B12 can be found in a variety of foods, including:
- dairy products
- nutritional yeast
- some fortified foods
Vitamin B12 binds to protein molecules in animal-based diets. Stomach acid separates it from the protein during digestion, and a chemical called intrinsic factor causes the bloodstream to absorb it.
A condition known as autoimmune atrophic gastritis causes some people’s bodies to produce insufficient stomach acid or intrinsic factor. Vitamin B12 shots may be required for these people to lower their risk of deficiency, which can develop to pernicious anaemia.
Those who have had gastrointestinal surgery and whose digestive system is unable to absorb vitamin B12 properly may also require shots.
What dosage of vitamin B12 do We require?
The recommended dietary allowances (RDAs) for vitamin B12 are listed in the table below. The RDA is the minimal daily quantity required by the majority of healthy people in a certain group.
|0–6 months||0.4 micrograms (mcg)|
|7–12 months||0.5 mcg|
|1–3 years||0.9 mcg|
|4–8 years||1.2 mcg|
|9–13 years||1.8 mcg|
|14+ years||2.4 mcg|
|Pregnant people||2.6 mcg|
|People who breastfeed||2.8 mcg|
A doctor, on the other hand, may provide advice on an individual’s specific needs.
Vitamin B12 shots
Vitamin B12 shots are a type of supplement that contains cyanocobalamin, a synthetic form of vitamin B12.
The shot will be administered by a doctor into the muscle. If they inject it into a vein, the body may lose a high amount of it through urine.
Cyanocobalamin is available in three different forms: liquid, tablet, and capsule. Certain foods, such as cereals, may be fortified with vitamin B12 in a synthetic form.
Who needs vitamin B12 shots?
Vitamin B12 injections can only be obtained with a prescription after a clinical diagnosis of low levels. Because the human liver accumulates vitamin B12 throughout time, low levels are uncommon in most healthy persons.
Some people, however, are at a higher risk of deficiency and may benefit from vitamin B12 injections or tablets.
Those suffering from vitamin B12 deficient symptoms
A doctor should be seen if you have symptoms of vitamin B12 deficiency or pernicious anaemia.
The following are some of the signs and symptoms:
- difficulty thinking and remembering
- heart palpitations
- pale skin
- weight loss
- numbness and tingling in the hands and feet
- mood changes
- a sore tongue
- low appetite
Vitamin B12 deficiency risk factors
The following risk factors can increase the chance of developing vitamin B12 deficiency:
- high alcohol consumption
- older age
- pernicious anemia
- atrophic gastritis, which refers to inflammation in the stomach
- Helicobacter pylori infection
- celiac disease
- Crohn’s disease
- a history of gastrointestinal surgery
- following a plant-based diet
- pancreatic insufficiency
- some hereditary conditions that affect vitamin B12 absorption
Those suffering from gastric people
Vitamin B12 release and absorption may be affected by gastrointestinal conditions.
These are some of them:
- pernicious anemia, which can lead to gastric atrophy, or damage to the stomach
- fish tapeworm infestation
- bowel or pancreatic cancer
- folic acid deficiency
- overgrowth of bacteria in the small intestine
- celiac disease
- Crohn’s disease
People who have had gastrointestinal surgery, such as weight loss surgery, may have less of the cells that secrete stomach acid and intrinsic factor. Vitamin B12 absorption may be affected as a result of this.
According to research published in 2015, vitamin B12 deficiency is more common in people over the age of 60, and certain people may benefit from vitamin B12 injections.
The researchers discovered that disorders linked to decreased stomach acid production, such as gastric atrophy, are more common in older persons. Low stomach acid also encourages the growth of some bacteria, which depletes vitamin B12 reserves.
Vegans and vegetarians
Because vitamin B12 is mostly found in animal sources, people who eat a plant-based diet are more likely to be vitamin B12 deficient.
In a 2010 study of 689 males, researchers discovered that those who ate a plant-based diet had greater rates of vitamin B12 insufficiency. Compared to just 1% of people who ate meat, over half of vegans and 7% of vegetarians had inadequate vitamin B12 levels.
Vitamin B12 is transferred to the infant through the placenta and breast milk, thus vegetarians and people who are pregnant may need to take supplements or eat fortified foods. If the baby is exclusively breastfed, he or she may not get enough vitamin B12. This can result in long-term and serious neurological problems.
A doctor may propose injections in rare circumstances, but research shows that taking extra vitamin B12 by mouth is just as beneficial as getting an injection in a muscle. It is also less expensive.
Vitamin B12 shots may be recommended by a doctor for people who are at risk of deficiency or its repercussions.
Vitamin B12 injections may help to lower your risk of developing the following conditions:
- heart disease
- neurological disorders
- problems with thinking and memory
- vision loss
- neural tube defects in children born to those with a vitamin B12 deficiency
Because the risk of toxicity or overdose is low, there is no upper limit for vitamin B12 intake. Vitamin B12 injections, on the other hand, may have unintended consequences.
If a person has any of the following symptoms, or if they persist or worsen, they should get medical help:
- pain, redness, or itching at the site of the injection
- mild diarrhea
- a swelling sensation in the body
- temporary itching of the skin
There may also be a risk of:
- pulmonary edema
- congestive heart failure
- peripheral vascular thrombosis, which involves blood clots
- polycythemia vera, which is a type of blood cancer
Anyone experiencing trouble breathing, hives, or swelling should seek immediate medical attention. They could be suffering from anaphylaxis, a life-threatening allergic reaction.
Certain drugs may interact with vitamin B12. Before obtaining a vitamin B12 shot, people should always tell their doctor about all prescription and over-the-counter medications they are taking.
The following are some of the most regularly prescribed drugs that may interact with vitamin B12:
- H2 receptor antagonists
- proton pump inhibitors
Medical disorders and allergies
Before having a vitamin B12 shot, anyone with allergies or medical issues should always consult a doctor.
Shots of vitamin B12 may not be appropriate for those who have a history of:
- hypokalemia, or low potassium levels
- deficiencies in other nutrients, particularly folic acid and iron
- sensitivity to vitamin B12
- Leber’s disease, which affects the optic nerve
- kidney problems
While most people obtain enough vitamin B12 from their diet, some people do not. This could be caused by low intrinsic factor levels in the digestive system, a digestive disease, or eating a plant-based diet.
The American Dietary Guidelines for 2020–2025 propose that vitamin B12 and other nutrients be met first and foremost through food.
If dietary sources are inadequate, a doctor may prescribe supplementation in the form of tablets or injections, depending on the cause of the deficiency.