Well, Looky Here

In July of 2004, exactly three years ago, I was diagnosed as having a lifelong blood disorder called hereditary spherocytosis. The oncologist who diagnosed me did so very quickly, and prescribed Folic Acid 1 mg daily (prescription). He said I'd have to take 1 mg of Folic Acid for the rest of my life. For the past three years, that is exactly what I have done.

For two of those three years, and most recently during the past six months, I've been experiencing worrisome neurological symptoms, as I've described in previous posts. My seizure-like episodes that occur at the onset of my monthly menstrual period have become extremely severe.

About three weeks ago, I stopped taking ALL vitamin, mineral and herbal supplements, including the Folic Acid. I was concerned that something I was taking may be causing these symptoms. I think I've pretty much cleansed my body of everything now, and I have to admit I do feel somewhat better. I also am not eating dairy except for very small amounts.

While I patiently await my appointment with the neurologist a month from tomorrow, several people have suggested that I may simply have B-12 deficiency. I started researching this, and I stumbled upon something this morning that astonished me. If an adult takes large doses of folic acid, it can actually TRIGGER symptoms of B12 deficiency. Permanent nerve damage can occur if B12 deficiency goes untreated. Since I'm a semi-vegetarian AND have a history of alcoholism (sober 19 years!) AND have spherocytosis which can cause anemia, I am not only at high-risk for B12 deficiency but also did not have my B12 levels checked prior to being prescribed Folic Acid.

If a doctor checks a person's B12 levels while that person is taking large doses of Folic Acid, the Folic Acid masks the B12 deficiency, resulting in a "normal" test result.

And guess what else? High levels of Folic Acid can trigger seizures in people with seizure disorders.

Here are some quotes I've taken off various web sites this morning:

Caution About Folic Acid Supplements
Beware of the interaction between vitamin B12 and folic acid
Intake of supplemental folic acid should not exceed 1,000 micrograms (μg) per day to prevent folic acid from triggering symptoms of vitamin B12 deficiency [10]. Folic acid supplements can correct the anemia associated with vitamin B12 deficiency. Unfortunately, folic acid will not correct changes in the nervous system that result from vitamin B12 deficiency. Permanent nerve damage can occur if vitamin B12 deficiency is not treated.

It is very important for older adults to be aware of the relationship between folic acid and vitamin B12 because they are at greater risk of having a vitamin B12 deficiency. If you are 50 years of age or older, ask your physician to check your B12 status before you take a supplement that contains folic acid. If you are taking a supplement containing folic acid, read the label to make sure it also contains B12 or speak with a physician about the need for a B12 supplement.

A word of caution: Folic acid can correct the nonneurologic signs and symptoms associated with vitamin B12 deficiency while masking the neurologic symptoms, allowing them to progress. Neurologic signs of vitamin B12 deficiency, normally reversible with B12 injectable supplements, may become permanent if left unchecked for too long. Any patient taking folic acid supplements who may have a vitamin B12 deficiency should be assessed for this possibility and treated if indicated.

What is the health risk of too much folic acid?
Folate intake from food is not associated with any health risk. The risk of toxicity from folic acid intake from supplements and/or fortified foods is also low [65]. It is a water soluble vitamin, so any excess intake is usually excreted in urine. There is some evidence that high levels of folic acid can provoke seizures in patients taking anti-convulsant medications [1]. Anyone taking such medications should consult with a medical doctor before taking a folic acid supplement.

The Institute of Medicine has established a tolerable upper intake level (UL) for folate from fortified foods or supplements (i.e. folic acid) for ages one and above. Intakes above this level increase the risk of adverse health effects. In adults, supplemental folic acid should not exceed the UL to prevent folic acid from triggering symptoms of vitamin B12 deficiency [10]. It is important to recognize that the UL refers to the amount of synthetic folate (i.e. folic acid) being consumed per day from fortified foods and/or supplements. There is no health risk, and no UL, for natural sources of folate found in food. Table 4 lists the Upper Intake Levels (UL) for folate, in micrograms (μg), for children and adults.

Caution: Folic Acid and vitamin B12 deficiency
Folic acid can correct the anemia that is caused by vitamin B12 deficiency. Unfortunately, folic acid will not correct the nerve damage also caused by vitamin B12 deficiency [1,36]. Permanent nerve damage can occur if vitamin B12 deficiency is not treated. Folic acid intake from food and supplements should not exceed 1,000 μg daily in healthy individuals because large amounts of folic acid can trigger the damaging effects of vitamin B12 deficiency [7]. Adults older than 50 years who take a folic acid supplement should ask their physician or qualified health care provider about their need for additional vitamin B12.

Upper Limit for Folic Acid Intake

Folic acid is water-soluble, which means excess amounts are usually excreted in the urine. However, the federal Office of Dietary Supplements (ODS) notes that the Institutes of Medicine has set an upper limit of 1 milligram per day for adults aged 19 and older. Almadori's study used a much higher dosage of folic acid, but it did not address any side effects.

Getting more than the upper limit of folic acid could trigger symptoms of vitamin B12 deficiency, states the ODS. Signs of vitamin B12 deficiency include anemia, fatigue, weakness, constipation, loss of appetite, weight loss, numbness or tingling in the hands and feet, and depression.

Such symptoms are also seen with other conditions, so check with your doctor about any concerns.

Toxicity Symptoms

What are toxicity symptoms for folate?

At very high doses greater than 1,000-2,000 micrograms, folate intake can trigger the same kinds of nervous system-related symptoms that it is ordinarily used to prevent. These symptoms include insomnia, malaise, irritability, and intestinal dysfunction. Primarily for these reasons, the Institute of Medicine at the National Academy of Sciences set a tolerable upper limit (UL) in 1998 of 1,000 mcg for men and women 19 years and older. This UL was only designed to apply to "synthetic folate" defined as the forms obtained from supplements and/or fortified foods.

Tips & Warnings
Ask your doctor for advice on how to safely add the recommended amount of folic acid to your diet.
Folic acid should not be taken in excess, since it can trigger symptoms of B12 deficiency.
Avoid foods that are fortified with folic acid if your diet includes a high amount of folic acid naturally.


  1. I have never met another person outside of my family who has spherocytosis, and I'd like to know if when you became vegetarian if you experienced a worse than average level of fatigue. Because I have recently become vegetarian, and I've become much more tired than I usually am. Also, did your doctor suggest to you not to eat red meat because of the possible iron overload?


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