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How Much Vitamin C Is
Too Much?
It’s generally accepted that a healthy dose of vitamin C can help
ward off colds. But just how much is enough?
Man is does not manufacture its own supply of vitamin C, also
known as ascorbic acid.
However, a 154-pound man would need to produce between 1.75 and
3.50 grams per day to keep up with the other animals.
There are experts who feel that taking more than 140 milligrams
per day of this vitamin is wasteful because, for many people, more than this
amount results in urine containing the vitamin—“Expensive Urine.”
The results of a test involving 88 patients, half being
schizophrenic, are reported in Dr. Linus Pauling’s book How to live Longer and Feel Better.
Each was given 1.75 grams of vitamin C by mouth. During the following
6 hours each patient’s urine was collected and then analyzed. The amounts
excreted varied from 2 percent to 40 percent of the amount ingested. The mental
patients excreted about 60 percent less than the others.
Incidentally, excreted vitamin C is not a complete loss. According
to Dr. Pauling, it protects against urinary tract infections.
Large doses can have a laxative effect causing looseness of the
bowel. This is said to be greater when the vitamin is taken on an empty
stomach.
Dr. Pauling recommended using this laxative effect to reduce
chances of developing colon cancer. Additionally, the vitamin appears to be
most effective in fighting disease when the dose is close to the bowel
tolerance limit.
It is notable that Dr. Pauling’s interest in vitamin C was sparked
by his observation that he and his wife experienced a striking decrease in the
number and severity of colds after they started taking large quantities of it.
However, physicians experienced with this therapy recommend
intakes near the bowel tolerance limit, said to be between 4 and 15 grams per
day for people in good health.
Dr. Irwin Stone, a pioneer in the use of vitamin C, recommended
taking 1.5 to 2 grams by mouth at the first sign of a cold and repeating the
dose at 20 to 30 minute intervals until symptoms disappeared. He said this
usually happened by the third dose.
There are many references in the scientific literature attesting
to the efficacy of vitamin C in wound healing.
It is interesting to note that your bones are made up of layers of
collagen and the mineral apatite which together form a matrix of
semiconductors. It is reasonable to believe, therefore, that vitamin C is also
of value in maintaining the integrity of your skeleton.
POISON?
There are those who say that large quantities of vitamin C are
poisonous.
Dr. Pauling reported that he took 18 grams of it every day and he
lived to be over 90.
Dr. Joel Wallach has stated that there are 60 minerals, 16
vitamins, 12 essential amino acids and 3 essential fatty acids that your body
requires in order to prevent dietary deficiency diseases.
Depression is the most frequently
searched-for topic at DoctorYourself.com.
Rather than give a synthetic drug to
block or mimic the body's chemical nerve messengers (neurotransmitters), it is
possible nutritionally to encourage the body to make its own natural ones.
MAKE YOUR OWN NOREPINEPHRINE
A depletion of the neurotransmitter called norepinephrine may
result in poor memory, loss of alertness, and clinical depression. The chain of
chemical events in the body resulting in this substance is:
L-phenylalanine (from protein foods)
-> L-tyrosine (made in the liver) -> dopa -> dopamine -> norepinephrine -> epinephrine
This process looks complex but actually
is readily accomplished, particularly if the body has plenty of vitamin C. Since one's dietary supply of the
first ingredient, L-phenylalanine, is usually adequate, it is more likely to be
a shortage of vitamin C that limits production of norepinephrine.
Physicians giving large doses of vitamin C have had striking success in
reversing depression. It is a remarkably safe and inexpensive approach to try.
MAKE YOUR OWN ACETYLCHOLINE
Acetylcholine is the end neurotransmitter of your parasympathetic nerve system.
This means that, among other things, it facilitates good digestion, deeper
breathing, and slower heart rate. You may perceive its effect as
"relaxation."
Your body will make its own
acetylcholine from choline. Choline is available in the diet as phosphatidyl
choline, found in lecithin.
Lecithin is found in egg yolks and most
soy products. Three tablespoons daily of soya lecithin
granules provide about five grams (5,000 milligrams) of phosphatidyl choline.
In fact, brain by dry weight is almost one-third
lecithin. In Geriatrics,
July 1979, lecithin is considered as a therapy to combat memory loss. Studies
at MIT show increases in both choline and acetylcholine in the brains of
animals after just one lecithin meal! Supplemental choline has even shown
promise in treating Alzheimer's Disease. (Today's Living, February,
1982). It also contains the valuable fish-oil-like, omega-3 linolenic acid.
Beef and sheep brains are also an
excellent source of lecithin.
Probably the best way to get a lot of
lecithin easily is to take lecithin GRANULES. Stir the granules quickly into
juice or milk. They won't dissolve, but rather will drift about as you drink. Lecithin granules can also be
used as a topping on any cold food. Ice cream comes to mind. Also, they are not
bad if stirred into yogurt. If you put lecithin granules on hot food, they will
melt and you will then have liquid lecithin.
All supplemental forms of lecithin are
made from soy beans. An alternate non-soy source is egg yolk. Generally,
maximum benefit is obtained when you eat the yolk lightly cooked (such as in a
soft-boiled egg).
MAKE YOUR OWN SEROTONIN
Before the FDA temporarily removed all tryptophan supplements from the market
due to a now-corrected, industrial manufacturing error, millions of people had
safely taken regular suppertime doses of this amino acid, usually 500–2,000 mg,
to help them sleep. Inside you, tryptophan is broken down into
anxiety-reducing, snooze-inducing niacin. Even more important, tryptophan is
also made into serotonin, one of your body's most important neurotransmitters.
Serotonin is responsible for feelings of well-being and mellowness. This is
such a profound effect that Prozac, Paxil, and similar antidepressants artificially keep the
body's own serotonin levels high. You can do the same thing naturally through
diet. And no one can tell us that beans, peas, cheese, nuts, sunflower seeds,
and good ol’
wheat germ are toxic if you eat a lot of them!
Plenty of carbohydrates in your meals
helps tryptophan get to where it does the most good: your brain.
Cheese and crackers provides a better
effect than the cheese standing alone. Poultry, especially the dark meat, is a
rich source of tryptophan. Add potatoes or stuffing, you can stay vegetarian
and still get tanked up on tryptophan.
Consider that five servings of beans, a few portions of cheese or peanut butter,
or several handfuls of cashews provide 1,000–2,000 mg of tryptophan, which will
work as well as prescription antidepressants.
Tryptophan is one of the ten essential
amino acids you need to stay alive. It is by law added to liquid feedings for
the elderly and all infant formulas.
Foods High in the Amino Acid
L-Tryptophan
(In milligrams per 100-gram (3.5 ounce)
portion, about the size of a deck of playing cards. That is not a large
serving, and in a single meal you might easily double or triple the figures
listed here.)
Beans
Lentils 215
Dried peas 250
Navy 200
Pinto 210
Red kidney 215
Soy 525
Nuts and Seeds
Brazil nuts 185
Cashews 470
Filberts 210
Peanuts 340
Peanut butter 330 (natural, not commercial)
Pumpkin seeds 560
Sesame seeds 330
Tahini (ground sesame seeds) 575
Sunflower seeds 340
Other nuts generally provide at least
130 mg per small serving; usually more.
Grains
Wheat germ 265
Cheese
Cheddar 340
Parmesan 490
Swiss 375
Other cheeses tend to be lower in tryptophan,
but are still very good sources.
Eggs 210
Poultry 250
Brewer's Yeast 700
Meats are generally regarded as a good
source of tryptophan, organ meats supposedly being the highest. However, most
meats are in the range of 160–260 mg/100 g, with organ meats ranging between
220 and 330. These figures certainly do not compel meat eating. They compel
split pea, cheese, and cashew eating!
VITAMIN B-6 AS AN ANTIDEPRESSANT
Ample amounts of B-complex vitamins,
especially B-6 (pyridoxine) must be present for for your body's normal,
depression-fighting chemical reactions to occur. The amount of B-6 needed for
clinical effectiveness in, say, rabbits is the human dose equivalent of 75 mg
daily. That is over 35 times more than the RDA!
Really enormous doses of B-6 taken
alone have produced temporary neurological side effects. It usually takes
between 2,000 and 5,000 mg daily for symptoms of numbness or tingling in the
extremities.
Some side effects have been reported as
low as 500 mg daily, but these are very rare indeed. Therapeutic doses between
100 and 500 milligrams daily are commonly prescribed by physicians for PMS
relief.
A daily total of a few hundred
milligrams of individual B-6, especially if taken in addition to the entire
B-complex to ensure balance, is very safe indeed.
Omega 3 helps prevent and fight heart disease, cancer,
depression, arthritis,
Alzheimer's disease, ulcers, diabetes, hyperactivity and other diseases. Omega
3 increases your ability to concentrate as well as your energy level.
While a helpful form of Omega-3 can be found in flaxseed,
walnuts and a few other foods, the most beneficial form of Omega-3 - containing
2 fatty acids, EPA and DHA which are essential in preventing and fighting both
physical and mental illness - can be found only in fish. Consuming a lot of
fish, whether naturally-caught or farm-raised, because fish of all varieties
from any waters are now showing dangerously high levels of the highly toxic,
tasteless metal, mercury.
The main difference between
fish oil and cod liver oil is that cod liver oil is high in vitamin D. The cod
liver oil has the advantage of providing vitamin D, which is necessary in
winter.
Many people get confused about the difference between fish oil
liquid and cod liver oil. You can consider cod liver oil as fish oil+. The 2
are the same except that cod liver oil contains natural vitamin D and A.
An additional way to increase omega 3 fats in your diet would be
to use freshly ground flax seeds .
Several studies and trials in humans have shown a favorable effect
of dietary cod liver oil and fish oil on various risk factors for cardiovascular
disease.
Studies have shown that the
Greenland Inuit, when compared with the population of
The traditional high-fat Inuit diet provides several grams of
omega-3 fatty acid (DHA and EPA) each day in the form of marine mammals (whale,
seal), wildfowl (seabirds) and various fish.
If you just listen to the 'experts', you would think that cholesterol
is an evil substance and that most of us would benefit from lowering our
cholesterol as low as possible. But
it's not so. Cholesterol is a vitally important substance which is used for
building our cell membranes and producing several of our hormones. If our
cholesterol level drops too low, we are actually at increased risk for depression.
Moreover, the higher fish intakes in the Japanese diet relative to
that of the
A European study of the effect of dietary omega-3 fatty acids -
such as cod liver oil and fish oil - on coronary atherosclerosis (measured with
coronary angiography) in people with cardiovascular
disease using a randomized,
double-blind, placebo-controlled trial showed improved health from the omega 3.
The study revealed that people with coronary artery disease given
omega-3 (DHA and EPA) therapy (at levels of about 1.5 g/day) over a 2-year
period had less progression and more regression of coronary disease, than did
patients taking a placebo. Fewer cardiovascular events (fatal and non-fatal
heart attacks, strokes)
were noted in the omega-3 group. The omega-3 supplementation was considered
safe and well tolerated.
All the patients had already tried prescription
drugs before enrolling in the
study, including selective serotonin reuptake inhibitors (SSRIs) such as
Zoloft, Paxil and Prozac, or drugs from an older family of drugs called
tricyclic antidepressants, all of which are considered standard treatments for
depression.
Previous studies have suggested that the balance of omega-3 fatty
acids in the brain may be skewed in people with depression, and earlier studies
have shown that cod liver oil and fish oil supplements can help alleviate the
symptoms of depression and schizophrenia.
If you take your omega 3 in liquid form, as opposed to capsules,
the dose for both the cod liver oil or fish oil liquid should be about 1-2
teaspoons per day. This is a good initial dose for most people but if you
notice any belching, it is likely that your gallbladder is not digesting the oil properly and
you may need to take a high potency enzyme with plenty of the fat
digesting enzyme lipase.
Ideally, you would want to measure your vitamin D levels.
Unfortunately very few doctors do this. But if you overdose on vitamin D you
can actually cause hardening of your arteries and osteoporosis as it causes a
reverse effect. In short, you take cod
liver oil during the winter months when our exposure to the sun is minimal, and
fish oil during the summer months.
If you use beneficial products like cod liver oil without doing
blood tests to check your vitamin D levels, you should keep the dose at 1 to 2
teaspoons per day to prevent overdosing or
switch to plain fish oil (which contains no vitamin D).
Use 1 teaspoon per day for a child. When you give your child cod
liver oil, you will also be supplying them with essential omega-3 fatty acids
which will maximize their brain development.
Dietary Supplement
Fact Sheet: Vitamin B6
Table of Contents
Vitamin B6: What is it?
What foods provide vitamin B6?
What is the Recommended Dietary Allowance for vitamin B6 for
adults?
When can a vitamin B6 deficiency
occur?
What are some current issues and controversies about
vitamin B6?
What is the relationship between vitamin B6,
homocysteine, and heart disease?
What is the health risk of too much vitamin B6?
Vitamin B6 intakes
and healthful diets
References
Vitamin B6 is a water-soluble vitamin that exists
in three major chemical forms: pyridoxine, pyridoxal, and pyridoxamine [1,2]. It performs a wide variety of functions in
your body and is essential for your good health. For example, vitamin B6 is needed for more than 100 enzymes
involved in protein metabolism. It is also essential for red blood cell
metabolism. The nervous and immune systems need vitamin B6 to function efficiently, [3-6] and it is also needed for the conversion
of tryptophan (an amino acid) to niacin (a vitamin) [1,7].
Hemoglobin within red blood cells carries oxygen to tissues. Your body needs
vitamin B6 to make
hemoglobin. Vitamin B6 also
helps increase the amount of oxygen carried by hemoglobin. A vitamin B6 deficiency can result in a form of
anemia [1] that is similar to iron deficiency anemia.
An immune response is a broad term that describes a variety of biochemical
changes that occur in an effort to fight off infections. Calories, protein,
vitamins, and minerals are important to your immune defenses because they
promote the growth of white blood cells that directly fight infections. Vitamin
B6, through its involvement in protein metabolism and cellular
growth, is important to the immune system. It helps maintain the health of
lymphoid organs (thymus, spleen, and lymph nodes) that make your white blood
cells. Animal studies show that a vitamin B6deficiency can decrease
your antibody production and suppress your immune response [1,5].
Vitamin B6 also helps
maintain your blood glucose (sugar) within a normal range. When caloric intake
is low your body needs vitamin B6 to
help convert stored carbohydrate or other nutrients to glucose to maintain
normal blood sugar levels. While a shortage of vitamin B6 will limit these functions,
supplements of this vitamin do not enhance them in well-nourished individuals [1,8-10].
Vitamin B6 is
found in a wide variety of foods including fortified cereals, beans, meat, poultry,
fish, and some fruits and vegetables [1,11]. The table of selected food sources of
vitamin B6suggests many dietary sources of B6.
Table of Food Sources of Vitamin B6 [11]
|
Food |
Milligrams (mg) |
% DV* |
|
Ready-to-eat
cereal, 100% fortified, ¾ c |
2.00 |
100 |
|
Potato,
Baked, flesh and skin, 1 medium |
0.70 |
35 |
|
Banana,
raw, 1 medium |
0.68 |
34 |
|
Garbanzo
beans, canned, ½ c |
0.57 |
30 |
|
Chicken
breast, meat only, cooked, ½ breast |
0.52 |
25 |
|
Ready-to-eat
cereal, 25% fortified, ¾ c |
0.50 |
25 |
|
Oatmeal,
instant, fortified, 1 packet |
0.42 |
20 |
|
Pork
loin, lean only, cooked, 3 oz |
0.42 |
20 |
|
Roast
beef, eye of round, lean only, cooked, 3 oz |
0.32 |
15 |
|
Trout,
rainbow, cooked, 3 oz |
0.29 |
15 |
|
Sunflower
seeds, kernels, dry roasted, 1 oz |
0.23 |
10 |
|
Spinach,
frozen, cooked, ½ c |
0.14 |
8 |
|
Tomato
juice, canned, 6 oz |
0.20 |
10 |
|
Avocado,
raw, sliced, ½ cup |
0.20 |
10 |
|
Salmon,
Sockeye, cooked, 3 oz |
0.19 |
10 |
|
Tuna,
canned in water, drained solids, 3 oz |
0.18 |
10 |
|
Wheat
bran, crude or unprocessed, ¼ c |
0.18 |
10 |
|
Peanut
butter, smooth, 2 Tbs. |
0.15 |
8 |
|
Walnuts,
English/Persian, 1 oz |
0.15 |
8 |
|
Soybeans,
green, boiled, drained, ½ c |
0.05 |
2 |
|
Lima
beans, frozen, cooked, drained, ½ c |
0.10 |
6 |
|
*
DV = Daily Value. DVs are reference numbers based on the Recommended Dietary
Allowance (RDA). They were developed to help consumers determine if a food
contains a lot or a little of a specific nutrient. The DV for vitamin B6 is
2.0 milligrams (mg). The percent DV (%DV) listed on the nutrition facts panel
of food labels tells you what percentage of the DV is provided in one
serving. Percent DVs are based on a 2,000 calorie diet. Your Daily Values may
be higher or lower depending on your calorie needs. Foods that provide lower
percentages of the DV also contribute to a healthful diet. |
||
The Recommended Dietary Allowance (RDA) is the average daily
dietary intake level that is sufficient to meet the nutrient requirements of
nearly all (97 to 98 percent) healthy individuals in each life-stage and gender
group [12].
The 1998 RDAs for vitamin B6 [12] for adults, in milligrams, are:
|
Life-Stage |
Men |
Women |
Pregnancy |
Lactation |
|
Ages
19-50 |
1.3 mg |
1.3 mg |
|
|
|
Ages
51+ |
1.7 mg |
1.5 mg |
|
|
|
All
Ages |
|
|
1.9 mg |
2.0 mg |
|
Results
of two national surveys, the National Health and Nutrition Examination Survey
(NHANES III 1988-94) [12,13] and the Continuing Survey of Food
Intakes by Individuals (1994-96 CSFII) [12], indicated that diets of most Americans
meet current intake recommendations for vitamin B6 [12]. |
||||
Clinical signs of
vitamin B6 deficiency
are rarely seen in the
Who may need extra vitamin
B6 to prevent a deficiency?
Individuals with a poor quality diet or an inadequate B6 intake for an extended period may
benefit from taking a vitamin B6 supplement
if they are unable to increase their dietary intake of vitamin B6 [1,15]. Alcoholics and older adults are more
likely to have inadequate vitamin B6intakes than other segments of
the population because they may have limited variety in their diet. Alcohol
also promotes the destruction and loss of vitamin B6 from the body.
Asthmatic children treated with the medicine theophylline may need to take a
vitamin B6supplement [16]. Theophylline decreases body stores of
vitamin B6 [17], and theophylline-induced seizures have
been linked to low body stores of the vitamin. A physician should be consulted
about the need for a vitamin B6 supplement
when theophylline is prescribed.
Vitamin B6 and the nervous system
Vitamin B6 is needed
for the synthesis of neurotransmitters such as serotonin and dopamine [1]. These neurotransmitters are required for
normal nerve cell communication. Researchers have been investigating the
relationship between vitamin B6 status
and a wide variety of neurologic conditions such as seizures, chronic pain,
depression, headache, and Parkinson's disease [18].
Lower levels of serotonin have been found in individuals suffering from
depression and migraine headaches. So far, however, vitamin B6 supplements have not proved effective
for relieving these symptoms. One study found that a sugar pill was just as
likely as vitamin B6 to
relieve headaches and depression associated with low dose oral contraceptives [19].
Alcohol abuse can result in neuropathy, abnormal nerve sensations in the arms
and legs [20]. A poor dietary intake contributes to this
neuropathy and dietary supplements that include vitamin B6 may prevent or decrease its incidence
[18].
Vitamin B6 and carpal tunnel syndrome
Vitamin B6 was first
recommended for carpal tunnel syndrome almost 30 years ago [21]. Several popular books still recommend
taking 100 to 200 milligrams (mg) of vitamin B6 daily to treat carpal tunnel syndrome,
even though scientific studies do not indicate it is effective. Anyone taking
large doses of vitamin B6 supplements
for carpal tunnel syndrome needs to be aware that the
Vitamin B6 and premenstrual syndrome
Vitamin B6 has become
a popular remedy for treating the discomforts associated with premenstrual
syndrome (PMS). Unfortunately, clinical trials have failed to support any
significant benefit [23]. One recent study indicated that a sugar
pill was as likely to relieve symptoms of PMS as vitamin B6 [24]. In addition, vitamin B6 toxicity has been seen in increasing
numbers of women taking vitamin B6 supplements
for PMS. One review indicated that neuropathy was present in 23 of 58 women
taking daily vitamin B6 supplements
for PMS whose blood levels of B6were above normal [25]. There is no convincing scientific
evidence to support recommending vitamin B6 supplements for PMS.
Vitamin B6 and interactions with medications
There are many drugs that interfere with the metabolism of vitamin B6.
Isoniazid, which is used to treat tuberculosis, and L-DOPA, which is used to
treat a variety of neurologic problems such as Parkinson's disease, alter the
activity of vitamin B6. There is disagreement about the need for
routine vitamin B6 supplementation
when taking isoniazid [26,27]. Acute isoniazid toxicity can result in
coma and seizures that are reversed by vitamin B6, but in a group of
children receiving isoniazid, no cases of neurological or neuropsychiatric
problems were observed regardless of whether or not they took a vitamin B6 supplement. Some doctors recommend
taking a supplement that provides 100% of the RDA for B6 when isoniazid is prescribed, which is
usually enough to prevent symptoms of vitamin B6 deficiency. It is important to consult
with a physician about the need for a vitamin B6 supplement when taking isoniazid.
A deficiency of
vitamin B6, folic acid, or vitamin B12 may increase your level of
homocysteine, an amino acid normally found in your blood [28]. There is evidence that an elevated
homocysteine level is an independent risk factor for heart disease and stroke [29-37]. The evidence suggests that high levels
of homocysteine may damage coronary arteries or make it easier for blood
clotting cells called platelets to clump together and form a clot. However,
there is currently no evidence available to suggest that lowering homocysteine
level with vitamins will reduce your risk of heart disease. Clinical
intervention trials are needed to determine whether supplementation with
vitamin B6, folic acid, or vitamin B12 can help protect you against
developing coronary heart disease.
Too much vitamin B6 can result in nerve damage to the arms
and legs. This neuropathy is usually related to high intake of vitamin B6 from supplements, [28] and is reversible when supplementation is
stopped. According to the
Vitamin B6 is
found in a wide variety of foods. Foods such as fortified breakfast cereals,
fish including salmon and tuna fish, meats such as pork and chicken, bananas,
beans and peanut butter, and many vegetables will contribute to your vitamin B6 intake. According to the 2005Dietary Guidelines for Americans,
"Nutrient needs should be met primarily through consuming foods. Foods
provide an array of nutrients and other compounds that may have beneficial
effects on health. In certain cases, fortified foods and dietary supplements
may be useful sources of one or more nutrients that otherwise might be consumed
in less than recommended amounts. However, dietary supplements, while recommended
in some cases, cannot replace a healthful diet."
The Dietary Guidelines for Americans describes a healthy diet as one that: