How Much Do You Need?

This information has been provided by Al Sears, MD and Doctor’s House Call. For more information or to sign up for a free subscription, visit


Health Alert 15

You are faced with a dilemma every time you shop for an herb, vitamin or nutritional supplement. You find what you are looking for and there on the shelf sets bottle after bottle of different amounts of the same supplement. How much do you need?

I encountered this problem recently. Imagine what you would do if it happened to you. Let’s say you are on vacation in the mountains of Colorado and your friend begins to suffer from mild altitude sickness. You know the best solution for this is the herb gingko biloba. You want to give her a dose of 200mg with plenty of water every 4 to 6 hours until she fells better.

You call the hotel convenient store to ask if they had gingko. Yea they have it. How much? The clerk doesn’t know. You walk down to the lobby and find the supplement packaged as six capsules in a plastic pouch for $5.95. The amount of gingko per serving is 10 mg. A serving has two capsules.

So to give 200 mg, you would have to give 20 servings or 40 capsules. Four times a day would be 160 capsules or about $160 per day. Of course even if you are willing to pay that much you wouldn’t want or expect anyone to swallow that many.

The point is that even if you know the correct remedy and can find it on hand you can’t use it for the desired effect unless you also know and can find the correct dose. Even at a high altitude store, the remedy that was on hand to treat altitude sickness could not be used in doses needed to be effective.

Adding to the problem, the labels can be hard to read and the choices daunting.

Even worse, sometimes the label won’t tell you the amount contained but has something like “proprietary blend”

Today’s Health Alert will provide you with a few simple rules you may find helpful. They have helped my patients.

* What You Need to Know about Nutrients with Known Requirements*

• The FDA is responsible for setting labeling requirements for vitamins and dietary supplements.

• The FDA has changed their system of naming several times and has created some confusion. What used to be called recommended daily allowance (RDA) was changed to minimum daily allowance. Recently it has been changed again to simply daily value (DV).

• All supplements that have a known minimum requirement are required to list their amount as a percentage of that minimum. Here is a list of the daily values of common nutrients.


Vitamin A 5,000 IU

Vitamin B6 2.0 mg.

Vitamin C 6O mg.

Vitamin D 400 IU

Vitamin E 30 IU

Calcium 1000 mg.

Phosphorus 1000 mg.

Zinc 15 mg.

Niacin 20 mg.

Magnesium 400 mg.

You should use this Daily Value as a reference point. It tells you how much of a nutrient is necessary to prevent symptoms of deficiency. It is important to note, however, that some nutrients have additional roles beyond preventing deficiencies see Health Alert #11

* How to Handle Supplements without Established Requirements *

• Realize that amounts are still important.

• If a supplement has any active ingredient without the amount specified, don’t take it.

• Know the amount of a supplement you want to take before you enter the store. Unfortunately, you cannot rely on the sales clerk.

Al Sears, MD