Owing to the increase in the popularity of the myriad of health benefits associated with vitamins, people often tend to ignore the deleterious effects vitamins can have when taken in excess, over a long period of time.
Even though, regular intake of natural food sources like whole grains, dairy products and organic fruits and vegetables serve as the best source for replenishing vitamins in the body, most people resort to convenient and instant ways by taking multi-vitamin supplements for making up for vitamin deficiencies in their bodies.
On the other hand, vitamin toxicity or hyper-vitaminosis can elicit adverse effects that can be as mild as nausea to something as severe as nerve damage. As per the National Institutes of Health (NIH), vitamins like thiamine (vitamin B1), riboflavin (vitamin B2) and biotin (vitamin B7) are not toxic, even when consumed in amounts beyond the recommended upper limit.
However, certain vitamins that have been listed below cannot be tolerated in excess and can instead become counterproductive, thus doing more harm than good to you. B vitamin toxicity is associated with many symptoms, one of them being, their ability to initiate nerve damage that in turn disrupts nerve impulse transmission.
Nerve Damage Due to Vitamin Over Dosage
Vitamin B3
Niacin or vitamin B3 plays a major role in flushing out toxins by maintaining a healthy metabolism, thus protecting the nervous system from damage. However, exceeding the recommended daily dosage by relying too much on synthetic vitamins can damage nerves and elicit major ill effects like faintness, dizziness, lightheadedness, flushing and headaches. Hence, the dietary reference intake (DRI) recommends a daily upper tolerable limit of100 mg of niacin for children and teenagers and 35 mg of niacin for adults.
Vitamin B6
Most abundantly found in fish, poultry, cereals, dark green vegetables and fruits, vitamin B6 or pyridoxine plays a crucial role in maintaining a healthy metabolic system, nervous system and immune system. Nevertheless, prolonged usage of vitamin B6 can cause permanent nerve damage, thus leading to numbness of hands and feet.
This loss of sensation, which is also termed as sensory neuropathy is the major cause of clumsiness in people who take in too much of vitamin B6 for increasing energy levels or to beat the symptoms of stress and anxiety. It leads to the overproduction of neurotransmitters like dopamine and serotonin in the body that can disturb the cognitive abilities of an individual.
Depression, mood swings, spine damage and headaches are also some of the most prominent symptoms of vitamin B6 toxicity. As per The Office of Dietary Supplements of the NIH, it is mandatory to limit your intake of vitamin B6 to 1.4 mg/day for men and 1.2 mg/day for women under the age of 50 and 1.5 mg for women and 1.7 mg for men, over the age of 50.
Vitamin B12
Cyanocobalamin or vitamin B12 deficiency is very rare since the cobalt found in vitamin B12 makes it the most stable vitamin that is hard to be destroyed by cooking and is directly absorbed in the intestine. Vitamin B12 is essentially involved in the production of red blood cells and in maintaining motor co-ordination in the body.
Its deficiency could lead to severe degeneration of neurons in the spinal cord. Nonetheless, vitamin B12 over dosage caused by the intake of synthetic supplements can exceed its tolerable upper intake and induce nerve damage characterized by numbness, itchiness and a burning sensation all over the body, especially the limbs.
Source: http://www.handclinic.nl/content.asp?id=236
A healthy diet including salmon, cod fish, herring, egg yolk, fortified cereal, beef liver and dairy products enables the body to obtain adequate levels of vitamin B12, thus allowing you to avoid B12 supplements and their related side effects. The recommended daily intake of vitamin B12 through dietary supplements varies between 0.4 – 2.5mg, depending on the age.
Vitamin D
Sunshine vitamin or vitamin D is crucially important for increasing the absorption of calcium and phosphorous in the body that are required for maintaining healthy teeth, bones and joints. Moreover, calcium serves as an important secondary messenger and initiates the release of neurotransmitters at the synaptic junctions, thus aiding in the propagation of nerve impulses.
Nevertheless, consumption of vitamin D supplements in surplus, without consulting a doctor can cause major side effects due to the excess deposition of calcium in the blood. Overproduction of neurotransmitters results from calcium overload, thus leading to pricking, numbness and pain in different body parts.
Also, hearing impairment can occur due to the damage done to the neurons located in the auditory centers of the brain. Hence, one should not exceed the recommended daily dosage of 250 micrograms/day (10,000 IU) of vitamin D to extract its benefits and keep its harmful effects at bay.
Vitamin K
Menadione or vitamin K plays a pivotal role in the production of red blood cells and acts as a cofactor for proteins involved in blood clotting, thus preventing hemorrhages. Conversely, megadoses of vitamin K leads to the destruction of blood vessels and slows down blood supply to the brain.
Source: http://www.medicinenet.com/blood_clots/article.htm
In infants, vitamin K overdose results in the deposition of pigments in the brain that causes considerable amount of damage to the nerves. The recommended daily allowance of 30 mcg for infants, 90 mcg for women and 120 mcg for men can thus be obtained through raw leafy vegetables, lettuce, broccoli, spinach and green tea, to avoid both vitamin K deficiency and overdose.
In contrast to the vitamins that are consumed through dietary sources, vitamins supplied to the body through supplements are not absorbed easily in the body. Hence, multi-vitamins are packed with very high dosages that are bound to elicit side effects. Moreover, exceeding the recommended daily allowance of the aforementioned vitamins or consumption of these vitamins for a long duration of time, without consulting a doctor can lead to long-term health complications.
Hence, before taking vitamin supplements, one should consider making healthy lifestyle changes and adapt natural ways of obtaining vitamins as opposed to reaching out for over the counter pills to avoid overdosing. Also, it is extremely important to consult a medical practitioner, before you start taking vitamin supplements to help you decide on the right dosage sufficient enough to treat your condition.
Caution: Please use Home Remedies after Proper Research and Guidance. You accept that you are following any advice at your own risk and will properly research or consult healthcare professional.