Doctors' Answers to "Frequently Asked Questions" - Vitamins

These comments are made for the purpose of discussion and should NOT be used as recommendations for or against therapies or other treatments. An individual patient is always advised to consult their own physician.

Bad Reaction to Vitamins [posted 1/6/99]
Question: I have a peculiar reaction to B-complex vitamins. I develop painful boils several days after starting the supplements. My physician is not familiar with this reaction and my own research has not found any reports of similar side effects. Have you heard of this reaction, and if so, which one of the B vitamins are causing it? I would like to continue taking supplements because they are otherwise quite beneficial.

Answer: Never seen it. I would look at the dyes, binders, etc., in your vitamin, not the Vitamin itself.

Chewing Vitamins [posted 11/11/98]
Question: Does chewing vitamins increase absorption by our bodies and increase their effectiveness?

Answer: Probably not.

Vitamin Complex [posted 8/14/98]
Question: I recently began taking a vitamin B complex. The supplement I take contains the following: Vitamin C 300 mg, Thiamin 15 mg, Riboflavin 10.2 mg, Niacin 50 mg, Vitamin B6 5 mg, and Pantothenic Acid 10 mg. I only take a half a tablet a day. I get a headache, which gets progressively worse each day until it is unbearable. It feels similar to a sinus headache, but much more intense and gets better after a few days of not taking them. I have not been able to find anything about this in any of the articles I have read. Anything you could tell me would be greatly appreciated.

Answer: None of these vitamins should be doing it.

Vitamins and Hypothyroid [posted 8/4/98]
Question: I am hypothyroid. Are there certain vitamins to avoid? I am confused regarding zinc, iodine, and iron as part of the vitamins.

Answer: Iron supplements can interfere with the absorption of the thyroid hormone, otherwise no real problems.

Vitamin E
Question: If Vitamin E is an oil when it is consumed, does it cause bile to be released into the digestive tract?

Answer: It doesn't seem to, or is minor at most.

Vitamin K cream
Question: I have been reading about vitamin K cream, and that it can help make spider veins go away. Is this so, and also, could using it make spider veins get worse?

Answer: I have heard of Vitamin E for this purpose but not Vitamin K. However, in small doses I doubt that it would harm you. I doubt it will have any effect

Vitamins
Question: When is the best time to take a multi-vitamin, with meals or on an empty stomach? Could a calcium supplement be taken at the same time or separately? Are there any particular foods to avoid eating at the same time as taking vitamins or calcium?

Answer: There are two types of vitamins-- water and fat soluble vitamins. Both appear to be absorbed best on an empty stomach, although food doesn’t make a major difference. If there is an iron supplement with the vitamins, it is absolutely absorbed best on an empty stomach.

Safe to take B12
Question: Is it safe to take 500 mcg B-12 per day? I am on: Vasotec 10 mg 2 times per day , Synthroid 0.1 mg per day, Zocor 10 mg per day , and Multivitamins and minerals.

Answer: There appears to be toxicity of oral B12. Excess B12 merely gets excreted by the kidney. There are vitamins which are potentially toxic. These are A, D, B6, and K.

Vitamin B
Question: Can you overdose or get to much of Vitamin B? What are the physical side effects? Are there any flu-like symptoms, such as dizziness or an upset stomach?

Answer: B complex vitamins are water soluble and generally are fairly non-toxic. However, Vitamin B6 has been reported to cause toxicity in very large doses. I would avoid industrial doses and keep to regular vitamin supplementation.

Vitamin A
Question: What is the highest recommended dose of vitamin per day? Also, what are the side effects of to much Vitamin A?

Answer: Vitamin A can be very toxic in high doses. High doses can cause death. In general, Vitamins A, D, and K are fat soluble and may be toxic in high doses. Therefore, it is given only by prescription. The toxicity of Vitamin A depends on the age of the patient, the dose, and the length of time given. Toxicity has been reported at 10 mg a day ongoing, or 100 mg with one dose.

Vitamin E
Question: Is it true that Vitamin E can cause a brain hemorrhage stroke? I am 81 years old and have Atrial Fib. I am currently taking Coumadin. My mother died of a stroke and I was wondering if I may safely take 400 mg of Vitamin E, or even more?

Answer: So far doesn't seem to. Fish oil and aspirin do, though. Vitamin E may also, but there is much less information available, and if so it is minimal.

Vitamin E General Info.
Question: What are the benefits of vitamin E?

Answer: Vitamin E is an essential vitamin and appears to be included in the group called antioxidants. There is a growing amount of research that indicates that Vitamin E(in doses over 200 units/day) may reduce strokes and heart attacks. Since there is currently no known toxicity to Vitamin E, it seems safe to take some until further definitive research is done. These studies(done in a randomized double blind manner) are currently underway.

Liquid Protein Suppliments
Question: I am a busy working female with not much time to really sit down and eat nutritionally sound meals. Therefore, I take supplements and eat as best as I can. In my latest order of vitamins/minerals I ordered liquid protein. Is it safe to take two ounces daily(an ounce twice daily)? Each ounce is about 14 grams of pre digested protein. Is it harmful to the kidneys, etc.? The recommended daily dosage is about an ounce three times daily with water. Is there any value in liquid protein?

Answer: Your body really doesn't care about the source of protein. Just that it has sufficient amino acids in the protein(variety) and that it has sufficient quantity. Protein per se is not harmful to the kidneys unless there is incipient renal failure. There are schools of thought that long term protein will damage renal function. But, this is hotly debated and mainly theoretical in concept.

Vitamin C Manufacturing
Question: Which companies manufacture vitamin C in China? Which Chinese companies manufacture vitamin C?

Answer: Sorry, no idea.

B-12 Level
Question: My vitamin b-12 levels are too low(255).

Answer: B-12 is a necessary vitamin for nearly every cell in the body and the nervous system uses a great quantity. B-12 is also the hardest vitamin to absorb. Occasionally, oral supplementation will not suffice to replace the deficiency. However, start taking 1000 mcg a month(ask your pharmacist it doesn't need a prescription) and recheck your levels in 3 months or so. If still low, you will need monthly injections(a real pain but necessary). It will take six months before your see the complete benefit from replacement and you can't overdose yourself with this vitamin.


Back to Drug InfoNet Home Page.