Massive doses of vitamin B12 can be bad for you
Q: Years ago, I started taking a vitamin B12 supplement. Over the past few years, I have had disabling pain in my feet diagnosed as nondiabetic neuropathy. The primary symptoms were burning, stabbing pain that felt like electric jolts.
Following extensive neurological testing, a nerve study revealed no abnormal nerve conduction in my lower limbs. A different neurologist related that he had seen a younger person with very similar symptoms from vitamin B12 toxicity. He asked me if I took this supplement and, if so, what dose.
I had been taking 1,000 micrograms a day; the recommended dietary allowance is 2.4 micrograms! I discontinued this supplement. Within 24 hours, my foot pain began to decrease. Within two weeks, nearly all my symptoms were gone.
Even though this dose is nearly 500 times the RDA, it seems to be very common. Apparently, vitamin B12 is considered nontoxic, watersoluble and quickly metabolized. Shouldn’t there be warnings about exceeding the RDA by so much?
A: Vitamin B12, or cyanocobalamin, is water-soluble, and reports of toxicity are extremely rare. In one case, however, a young woman was treated with 1,000 micrograms of vitamin B12 daily to correct a deficiency (Clinical Toxicology, February 2020). She developed insomnia, headache, palpitations, anxiety and acne.
The researchers who published the case described her symptoms of toxicity as “unexpected and unusual.” Fortunately, she recovered within two weeks of stopping the supplement.
Unless a doctor prescribes 1,000 micrograms (1 milligram) to correct a deficiency, most people should be taking a much lower dose of vitamin B12.
Q: Could you comment on the value of taking hawthorn berry tincture for heart health? Are there any studies on this?
A: You might be surprised to learn that hawthorn herbal products have been used to treat cardiovascular problems in China since 659 A.D. (Frontiers in Pharmacology, Feb. 21, 2020). Researchers have found that hawthorn can relax blood vessels, lower blood fats, reduce inflammation and fight oxidation. These all suggest that hawthorn could be helpful for heart health.
A review of the evidence of a specific hawthorn extract, WS 1442, considered clinical trials as well as nonclinical research and post-marketing reports (American Journal of Cardiovascular Drugs, February 2018). It is used to help moderate blood pressure and normalize heart rhythm. The authors concluded that the scientific evidence supports the use of this extract for people with mild to moderate heart failure.
One reader was taking prescription pills for high blood pressure. The doctor reluctantly agreed to let the patient try hawthorn tincture. To her surprise, the blood pressure was under good control after six weeks. Like our reader, anyone who considers using hawthorn extract or tincture should work with a physician to make sure the desired results are achieved.
Q: Is there any problem taking alprazolam to get to sleep? I’ve been doing this for years. Would melatonin work as well?
A: Alprazolam (Xanax) is a benzodiazepine approved for anxiety but not insomnia. Benzos are considered inappropriate for older people. Stopping may make sleeping much harder, though, and requires medical supervision.
Melatonin won’t substitute for alprazolam, but it may help you readjust your sleep-wake cycle (Neuropsychopharmacology, July 2022).
You can learn more about alprazolam, melatonin and many other strategies for overcoming insomnia in our eGuide to Getting a Good Night’s Sleep. This online resource is available under the Health eGuides tab at PeoplesPharmacy.com.