Low levels of B12 cause a reduction in the formation of red blood cells. The blood cells don't develop properly, and are unable to move into the bloodstream at the correct rate. This can lead to anaemia, a condition in which not enough oxygen is transported to the vital organs. This can lead to fatigue and weakness.
One Possibility: Supplement Allergies
Thus if you're otherwise healthy but still continue to feel tired after taking a B-12 supplement, it could be a sign of a mild allergic reaction. If a rash, difficulty breathing or swelling coincides with taking your dose of B-12, get to the doctor right away.
Vitamin B12 deficiency can cause pronounced symptoms of exhaustion and fatigue, even in the low normal range. This cause should therefore always be considered in the context of the symptom fatigue and also tested for in the laboratory.
Too much nicotinic acid can also cause low blood pressure, fatigue, headaches, rashes, and liver damage. Excess nicotinamide. High doses of nicotinamide, another form of vitamin B3, can cause diarrhea and increased bleeding. This can occur in doses of 500 mg per day.
The reaction is thought to occur due to impurities in the B12 injection, notes Drugs.com. If a reaction occurs it is usually within several weeks after the first injection. Symptoms of an allergic reaction include difficulty breathing, swelling of the face and airway and hives.
Some of the negative side effects of vitamin B overdose include mood swings, restlessness, depression, and panic attacks. Mood swings can worsen in people who suffer from paranoia, confusion, or mental fogginess; due to the high doses of vitamin B complex.
Experts say the vitamin can boost mood, energy, memory and more in folks who are deficient. B12 is a nutrient needed to form red blood cells, DNA, and brain and nerve cells. In deficient people, the benefits of B12 injections include improved mood and increased energy levels.
Fatigue. Megaloblastic anemia due to vitamin B-12 deficiency may lead to a person feeling fatigued. Without enough red blood cells to carry oxygen around their body, a person can feel extremely tired.
It may take a few weeks before your vitamin B12 levels and symptoms (such as extreme tiredness or lack of energy) start to improve. If you have hydroxocobalamin injections to boost your vitamin B12 levels at the start of treatment, the cyanocobalamin tablets may start to work within a few days.
Once you begin treating your vitamin B12 deficiency, it can take up to six to 12 months to fully recover. It is also common to not experience any improvement during the first few months of treatment. If you can, it's a good idea to address what's causing the deficiency.
When taken at appropriate doses, vitamin B-12 supplements are generally considered safe. While the recommended daily amount of vitamin B-12 for adults is 2.4 micrograms, higher doses have been found to be safe. Your body absorbs only as much as it needs, and any excess passes through your urine.
Possible Interactions
Medications that reduce levels of B12 in the body include: Anti-seizure medications -- including phenytoin (Dilantin), phenobarbital, primidone (Mysoline) Chemotherapy medications -- particularly methotrexate. Colchicine -- used to treat gout.
Vitamin B12 shots work right away and your body will begin to manufacture new red blood cells as early as 48 hours so you will feel the effect in two or three days. B12 injections work faster than oral supplements of B12 and therefore, are recommended for individuals who need quick improvement.
Vitamin B12, for example, should definitely be taken in the morning. This is because it is important for energy metabolism, which may interrupt your sleep if taken at night.
Many people consider dietary supplements to be safe, but some may also cause fatigue. Two examples of supplements associated with fatigue are tryptophan and collagen. Collagen (derived from the Greek words kola [“gum”] and gen [“producing”]) is found throughout the human body.
It was found that 96 percent of respondents reported "unusual fatigue". As per experts, fatigue is one of the primary signs of B12 deficiency, which could be more prevalent in the morning when you wake up.
B12 injections may contribute to low potassium levels in your body. Though rare, this reaction can cause muscle cramping, extreme fatigue, and an irregular heartbeat.
Vitamin B12 Blood Test
Our Active B12 blood test is the most accurate way to measure the amount of vitamin B12 that is available for the body to use, helping to identify any deficiency that could be causing your symptoms.
People with vitamin B12 deficiency can have neurological symptoms and/or damage without anemia (lack of red blood cells). General physical symptoms of vitamin B12 deficiency can include: Feeling very tired or weak. Experiencing nausea, vomiting or diarrhea.
Stage 1 is decreased levels of vitamin B12 in the blood. Stage 2 is low concentration of vitamin B12 in the cell and metabolic abnormalities. Stage 3 is increased levels of homocysteine and MMA and decreased DNA synthesis resulting in neuropsychiatric symptoms. Stage 4 is macrocytic anemia.
Vitamin B12 deficiency anaemia is usually treated with injections of vitamin B12, called hydroxocobalamin. At first, you'll have these injections every other day for 2 weeks or until your symptoms have started improving. Your GP or nurse will give the injections.
Common side effects
These symptoms are usually mild and should only last a few hours. You can ask a pharmacist to recommend a mild painkiller if the pain is bothering you.
Mild overdose of Vitamin B can cause problems like Headache, Upset stomach, and Weakness of the body. Acute overdose can cause symptoms like Cardiac arrhythmia i.e, irregular heartbeats, Hypotension, convolutions, a key symptom for thiamine overdose is lips turning blue.