How Much Vitamin D is Too Much? Take This Vitamin D Quiz to Find Out!

[Guest guest]

http://www.mercola.com/2003/dec/27/vitamin_d_quiz.htm

 

 

How Much Vitamin D is Too Much? Take This Vitamin D Quiz to Find Out!

 

 

 

 

 

Dr. Mercola's Comment:

 

 

 

This quiz on vitamin D toxicity is an excellent follow-up to , as there is still

much confusion about vitamin D and vitamin D toxicity. I encourage you to take

the quiz and even pass it along to your doctor, as very few U.S. physicians are

aware of vitamin D’s importance.

 

Winter is the time of year when most of us in the United States need to be very

diligent about keeping our vitamin D levels within optimal levels. I recommend

that most take a high-quality cod liver oil, which is an excellent source of

vitamin D, regularly from fall until early spring. However, it is essential to

understand that in order to know how much vitamin D you should be taking, you

should get your blood level checked. If you use beneficial products like cod

liver oil without doing blood tests for vitamin D levels, you should keep the

dose at one to two teaspoons per day to prevent overdosing.

 

This is a major point: excess vitamin D will cause, not prevent, osteoporosis

and hardening of your arteries. Please be very careful with cod liver oil. If

you are unable to obtain vitamin D testing, then please do not exceed one to two

teaspoons of cod liver oil. So please do yourself a favor--read the article on

vitamin D testing and be sure to have your level measured. As I mentioned above,

nearly all physicians are not aware how to have this checked and how to

interpret the normal reference ranges, so I encourage you to print out the

article on vitamin D testing not only for your own records but also for your

doctor so he or she can become aware of this vitally important nutrient.

 

The Vitamin D Council, the non-profit group that contributed the excellent quiz

below, is another great resource for vitamin D information. The Vitamin D

Council is a group of citizens concerned about vitamin D deficiency and the

diseases associated with that deficiency. I encourage you to check out their

website and sign up for their informative newsletter. Their goal is an important

one: to draw attention to the problem of vitamin D deficiency through the

education of professionals, the media, government officials and average

citizens.

 

 

 

By John Jacob Cannell, M.D.

Executive director of The Vitamin D Council

 

 

 

1. If an otherwise healthy adult tried to kill himself by taking an entire

bottle (250 capsules) of 1,000 iu cholecalciferol, which of the following would

happen?

 

a) The person would die within 24 hours from severe hypercalcemia and widespread

calcinosis.

b) If the person received intensive treatment for hypercalcemia he may survive.

c) Hypercalcemia would be severe but require only supportive treatment.

d) Such doses are called " Stoss " therapy and are occasionally used

therapeutically although they do not replicate normal physiology. As most

Americans are vitamin D deficient, such a one-time dose would probably be a

health benefit for the majority of Americans.

 

The correct answer is d. One of the most recent examples is the use of stoss

therapy to reduce fracture rates in the elderly (100,000 IU of oral

cholecalciferol every four months for five years) by Dr. Trivedi and colleagues

(University of Cambridge School of Clinical Medicine) published in the British

Medical Journal. How high do you think average 25-hydroxyvitamin D levels were

in the subjects after they received 100,000 IU of cholecalciferol every four

months for five years? Answer: about 29 ng/ml, still mildly deficient! (Source)

 

2. Acute poisoning leading to rapid death from ingestion of vitamin d capsules

(successful suicide attempt),

 

a) Has frequently been reported in the literature.

b) Has occasionally been reported in the literature

c) Has never been reported in the literature.

 

The answer is C, as far as we know. If you know of a report of a successful

suicide attempt, accidental death or murder from overdosing on vitamin D

supplements, let us know. We do know of one interesting case that demonstrates

the relative safety of vitamin D. Industrial strength crystalline vitamin D was

added to table sugar, either by accident or on purpose. The two men poisoned

were getting about 1,700,000 IU of cholecalciferol every day for seven months.

Again, they were getting at least, 1,700,000 units [440 times the Institute of

Medicine's toxicity warning (LOAEL)] every day for seven months! Both got very

sick but recovered. (Source)

 

3. True of false: water has a higher (safer) therapeutic index (the median

lethal dose divided by the median effective dose) than cholecalciferol?

 

a) True

b) False

c) About the same

 

The answer is b. Although exact human studies have never been done for obvious

ethical reasons, water intoxication leading to hyponatremia, cerebral edema and

occasional death is common in psychiatric populations and may become evident if

one drank 80 glasses of water a day, instead of eight. Heaney, et al, recently

showed healthy humans utilize about 4,000 IU of cholecalciferol a day, if they

can get it. 40,000 IU a day is certainly not acutely toxic. In fact, some

research reported that young white humans get up to 50,000 IU from one full body

summer sun exposure. (Source)

 

4. If a person totally avoided the sun and regularly took two standard

multivitamins a day for several years, each containing 400 iu of ergocalciferol,

as his sole source of vitamin d, he would,

 

a) Rapidly become vitamin D toxic and require medical attention for symptoms of

hypercalcemia.

b) Slowly become vitamin D toxic and eventually become symptomatic.

c) Slowly develop hypervitaminosis D but remain asymptomatic.

d) Obtain a healthful vitamin D blood level.

e) Inexorably become vitamin D deficient.

 

The answer is e. Two standard multivitamins contain 800 IU of ergocalciferol,

equivalent to about 500 IU of cholecalciferol. If you totally avoided the sun,

as many dermatologists routinely recommend with impunity (so far), one would

have enough vitamin D to prevent rickets and osteomalacia but would still have a

suboptimal 25-hydroxyvitamin D and thus be at risk to develop numerous other

chronic inflammatory diseases, not just osteoporosis. For a review of such

illnesses, see Zittermann. (Source)

 

The key is " totally avoided the sun. " Remember, most people get 90 percent of

their vitamin D requirement from very casual sun exposure, like the sunlight

that strikes the uncovered and unsunblocked face, arms and hands when you walk

to your car. Vitamin D production in the skin is that fast. Of course, some

people follow their doctor's advice and take obsessive steps to prevent sunlight

from ever striking their unprotected skin. A host of chronic inflammatory

diseases may await the patients who follow such advice, just as trial lawyers

may await the doctors that give it.

 

5. Of the three medications listed below, which is the safest in overdose?

 

a) Vitamin D (250 of the 1,000 IU capsules)

b) Aspirin (250 of the 325 mg tablets)

c) Tylenol (250 of the 500 mg tablets)

 

The answer is a. In fact 250,000 IU of vitamin D at one time is used as " stoss "

therapy, especially in Europe. For a review of many such studies and the doses

needed to achieve toxic 25-hydroxyvitamin D levels, see Vieth. (Source)

 

6. Which drug has the highest (safest) therapeutic index?

 

a) Depakote

b) Lithium

c) Coumadin

d) Dilantin

e) Synthroid

f) Theophylline

g) Cholecalciferol

 

The answer is g. All of the medication listed except cholecalciferol have narrow

therapeutic indices and can easily cause death in overdose. Such is not true for

vitamin D and, because of the huge number of capsules needed, is not likely

unless one has the industrial strength compound. See below for a sample

calculation.

 

7. In 1997, adams and lee wrote a widely publicized paper about vitamin d

toxicity in the annals of internal medicine. The adams and lee paper was

accompanied by a stern editorial warning of the dangers of vitamin d written by

marriott of the national institute of health. The three authors,

 

a) Correctly diagnosed all five of the patients

b) Were thanked by nationally acclaimed vitamin D scientists for their

contributions to understanding vitamin D toxicity.

c) Showed frightening ignorance about vitamin D toxicity and appeared not to

know the difference between the two standard deviation upper limit of a Gaussian

distribution and levels known to reflect vitamin D toxicity.

 

The Adams and Lee paper and the editorial by Dr. Marriott are a continued

embarrassment to the usually stellar Annals of Internal Medicine. However, the

papers are instructive in that they remind us that otherwise educated and

intelligent research physicians can confuse the two standard deviation upper

limits of a Gaussian distribution with toxicity. For a more detailed critique,

as well as several other problematic articles about vitamin D, see this link.

 

8. By sunbathing for a few minutes in the noonday summer sun, one can easily

obtain five times the vitamin d toxicity warning (lowest observed adverse

effects level or loael) of the institute of medicine's food and nutrition board.

 

a) True

b) False

 

The answer is a, at least for young whites. The IOM lists the Lowest Observed

Adverse Effects Level (LOAEL) as 3800 IU for vitamin D. Studies show young

whites can make between 10,000 to 25,000 IU in a single, relatively brief, sun

exposure. Numerous factors affect the body's ability to make such high amounts

of cholecalciferol, with age, race, latitude, clothing, season and sunblock

being the main factors. (Source)

 

9. If humans are twice as sensitive as the most sensitive mammal tested (male

rats), then a 110-pound human would have to injest 88,000 capsules (352 bottles

containing 250 of the 1,000 iu capsules) of cholecalciferol in order to have a

50 percent chance of dying (ld50) from an acute overdose.

 

a) True

b) False

 

False, about 168 bottles would do it. The LD50 for male rats (the most sensitive

mammal tested) is 42 mg/kg. If humans were twice as sensitive that would be an

LD50 of 21mg/kg or 21,000 ug/kg or 1,050,000 ug for a 50 kg human which is

42,000,000 units or 42,000 capsules or 168 bottles of the 250 capsules of 1,000

IU cholecalciferol. [Dorman DC (1990) Toxicology of selected pesticides, drugs,

and chemicals. Anticoagulant, cholecalciferol, and bromethalin-based

rodenticides. Vet Clin North Am Small Anim Pract 20(2):339-352].

 

10) As most american blacks suffer from vitamin d deficiency, some black

activists feel unwarranted fear and scare techniques about vitamin d toxicity

may be racially motivated. That is, racists may be intentionally repeating and

promulgating vitamin d toxicity scares in order to prevent relevant government

agencies from dealing with the problem of widespread vitamin d deficiency in the

black community.

 

a) True

b) False

 

True. The recent NIH conference on vitamin D was most interesting in this

regard. Very few Blacks were attendees but several were helping with

registration. As the conference progressed into the second day, Blacks helping

with registration began to listen to the lectures and became increasingly angry

as speaker after speaker pointed out how vitamin D deficiency adversely impacts

the black community. One young black man told a sad story of how his infant son

was recently diagnosed with rickets. Although the 1997 Food and Nutrition Board

was an all-white board, most of the Blacks were angry that nothing is being done

currently.

 

Certainly, it is true that one of the most effective ways to paralyze the

government into continued inaction on the pandemic of vitamin D deficiency would

be to raise false and frightening toxicity fears. However, remember that it is

easy to suspect vast conspiracies, but in the end it is usually simple

incompetence. That is certainly true of the mistakes I've made in my life.

 

11. In the most recent case of vitamin d toxicity described in the literature, a

man recovered uneventfully after taking a health supplement every day for two

years that contained 156,000 iu of cholecalciferol.

 

a) True

b) False

 

True. Actually, it is likely he took more than that. An industrial manufacturing

error was implicated. Such reports help confirm what is known from animal data

and that is that it takes a lot of vitamin D to hurt you, but it can be done.

(Source)

 

12. One of the world's foremost authorities on vitamin d metabolism and

physiology recently said, " worrying about vitamin d toxicity is like worrying

about drowning when you are dying of thirst. "

 

a) True

b) False

 

True. The quote is from one of the vitamin D scientists listed below. One of the

problems is that there are so few vitamin D scientists in the world, that

misconceptions, especially about toxicity, are the rule rather than the

exception, even among medical researchers.

 

In 1999, Dr. Reinhold Vieth, perhaps the world's leading expert on vitamin D

toxicity and metabolism, wrote a systematic and scholarly review of the world's

literature debunking the hysteria surrounding fears of vitamin D toxicity.

(Source)

 

Later, Vieth demonstrated the safety of daily dosing with 4,000 IU of

cholecalciferol, a dose that exceeded the current toxicity warnings of the IOM's

FNB. (Source)

 

Two years later, Heaney, et al, demonstrated the safety of doses up to 10,000 IU

a day while also demonstrating for the first time that healthy humans utilize

3,000 to 5,000 IU of cholecalciferol a day (10 times the Institute of Medicine

Food and Nutrition Board's current recommended Adequate Intake). What the human

body does with such high amounts of cholecalciferol remains unknown, but we

suspect Nature has a plan. (Source)

 

In a reply to critics of his paper, Vieth challenged anyone in the scientific

community to present even a single case of vitamin D toxicity in adults from

ingestion of up to 1,000 ug (40,000 IU) a day of cholecalciferol saying, " I

welcome any discussion of evidence of harm with vitamin D3 (not D2) in adults at

doses <1,000 ug/d. " Vieth's challenge remains unanswered and his work remains

unrefuted. (Source)

 

 

Related Articles:

RDAs of Vitamin D Far Too Low

 

Millions of U.S. Youth at Risk of Vitamin D Deficiency

 

Vitamin D for Cancer

 

Milk Not Useful in Raising Your Vitamin D Levels

 

Vitamin D Treats Congestive Heart Failure

 

Even Breastfed Babies Deficient in Vitamin D

 

 

 

 

 

Photos - Get your photo on the big screen in Times Square