One of the tricky parts when it comes to vitamins and minerals is how much to take. To make it especially confusing, there are several different reference scales available. The three I mentioned in my last post were RDA (Recommended Daily Allowances), ODI (Optimum Daily Intake) and SONA (Suggested Optimal Daily Nutritional Allowances). The RDAs were updated in 1993 with Reference Daily Intake (RDI) which is supposed to represent an average need. RDA/RDI values are pretty much the same, and are the values that the percent daily values (%DV) on nutrition labels are based on. The ODI is a value used in The Real Vitamin and Mineral Book by Shari Lieberman and Nancy Bruning and in most cases is higher than the RDA & SONA values. The SONA values are based on 15 years of health evaluations done on 13,500 people from six different areas in the United States. SONA and ODA (Optimum Dietary Allowances) are similar and you may see them used somewhat interchangeably. You can read more about the values and what they all mean here. It’s a Food Technology blog post that I found. It says the same thing I have read but it’s done in one paragraph where as the information I read is covered in four books. I figured the blog post would be an easier reference point. I site the books I have read at the end of this post.

So, that’s all lovely and confusing. Why all the different recommended numbers? Well, the RDA’s were developed back during World War II and they represent a value that is supposed to keep the average healthy person well. Here’s a quote from the Food Technology blog that I linked to above:

…SONA values (Suggested Optimum Nutritional Allowances), which happen to be the most comprehensive data on nutrients evolved over many years of studies with thousands of healthy people. SONA values are some times 20 times that of RDI because it takes into consideration the positive benefits of nutrient intake while RDI values are for minimum nutrition below which there can be deficiency symptoms.

In my reading I came across a description of RDAs as the minimum wage of vitamins and minerals. I thought that was a pretty clever way to explain why we are seeing competing “optimal” allowance values. Here is a quote from The Real Vitamin and Mineral Book that puts RDAs in perspective:

They are probably high enough to keep you alive – although even this is open to question. But they do not appear high enough to allow you to enjoy the best quality of life. And why should you not strive for the best?

That pretty much sums up my current, personal feelings about vitamin and mineral supplementation. I feel pretty good but I wouldn’t mind feeling GREAT! I’m also a little concerned about my life long lack of some sort of supplemental vitamin and the underlying deficiencies that may have been building for years. Hopefully I can begin to correct any damage that has been done.

The RDIs have three basic problems: 1) you cannot get all of the nutrients you need from today’s food; 2) the RDIs reflect amounts that are adequate to prevent nutrient-deficiency diseases and are not tailored for individual needs; and 3) the RDIs do not address or consider optimum health or the prevention of degenerative diseases such as cancer and heart disease.

The Real Vitamin and Mineral Book

You can read more about each of the above points in the book if you are so inclined. I’ll go into a little more detail about the first one since this used to be my rational for not needing to take vitamins and minerals. RDAs are based on a “balanced diet”. How many people eat a balanced diet? I think I eat a pretty balanced diet and a week of analysis showed that I wasn’t even coming close to the RDIs – that freaked me out. Once I realized I wasn’t hitting the RDIs I increased my consumption. I had to eat close to 2500 calories to even come close to hitting the RDIs (minimum wage) with just my food. Most people don’t eat nearly that much in a day. Let’s face it, everyone is on a diet. If the average female dieter is eating 1800 calories a day that’s a lot. The food we get from the grocery store is not as nutritious as the food our grandparents ate. The soil is depleted and the nutrient content of the food we buy is dependent on the soil it’s grown in. Buying organic is a step in the right direction but if my diet analysis was correct, which I believe it was, organic foods weren’t enough to push my nutrient values even to the “minimum wage”. I recently learned that the midwest, great lakes region and eastward are “low-selenium” areas. I had no idea that food grown in my area of the country is probably lacking in selenium – how are we supposed to know that stuff?! Selenium is a powerful antioxidant and anticancer mineral. That seems important. I would surely like to know if that was missing from my “healthy” diet and do something about it (which I now am). Even the fruits and veggies that are grown in healthy soil start to lose their nutrients as soon as they are picked. If you aren’t buying local, those fruits and veggies are hanging around a long time before you get them home from the store. Ouch.

  • Food in the United States travels 1,300 miles from farm to market shelf, on average
  • Nearly every state buys 90 percent of its food from outside the state.
“The Ethics of Eating,” National Catholic Reporter, May 24, 2002.
Basically, the RDA/RDIs don’t cut it. A lot of really smart people have spent years trying to figure out what the optimal levels for vitamins and minerals are. I’m feeling pretty comfortable with what I read and the SONA values. I want my intake levels to be higher than the RDIs and probably close to what is currently considered the Suggested Optimal Daily Nutritional Allowances (SONA). The SONAs are pretty high so it will probably take time for me to work up to that level (remember the choking/gagging problem I have). I’ll probably try to investigate as many alternatives to tablets and capsules as I can find. I still plan to TRY and get all my nutrients through food but now that I know that’s close to impossible I will continue to supplement.
If you are using supplements or thinking about buying supplements here are a few things to consider:
  • The bottles should be dark or opaque to protect the contents from light
  • There should always be a date of production, an expiration date and a lot number
  • Each nutrient should be listed and anything else in the tablet or capsule should be listed such as: binders, fillers, excipients, lubricants, disintricants, colorants, sweeteners, flavors or coating materials
  • If the label dosen’t EXPLICITLY state that there are no binders, fillers or excipients then you can be certain they are in your vitamin
  • Tablets can not be manufactured without excipients, capsules can but may not be excipient-free.
  • Buy natural over synthetic when possible (ex. natural vitamin E is 3x more absorbable than synthetic vitamin E).
Here’s a quick description of Excipients:
Supposedly inert substances that are added to the vitamin to help create a desired consistency or form. Nothing is truly “inert” which means some of these substances can cause problems for sensitive people.
  • Fillers – used to take up empty space in a capsule or tablet. Talc and silicon are examples of non-food grade fillers. Examples of food-grade fillers are corn starch, lactose, cellulose, sorbitol and calcium phosphate.
  • Flowing Agents and Lubricants – prevent raw materials for the vitamin from clumping or caking while being manufactured or after manufacturing when stored. The lubricants stop tablets from sticking to manufacturing equipment during the manufacturing process. Common lubricants: vegetable stearin (similar to shortening), magnesium stearate, calcium, stearate, stearic acid and silicates. Some of these may reduce bioavailability because they increase the time it takes the body to dissolve the supplement.
  • Binders – hold raw materials together in order to form tablets. Common binders: cellulose, gum arabic, lecithin, honey, and sorbitol.
  • Disintegrants – help tablets break down after they are consumed. Most common disintegrant is modified cellulose
  • Colorants – for looks. Bunches of synthetic coloring agents are approved by the FDA. The best are natural color agents like beets, carrots or chlorophyll.
  • Flavors/Sweeteners – will pretty much find these in liquids, chewables and some powders. Common sweeteners: fructose, malt dextrose, sorbitol or maltose. Some contain stevia.
  • Coating Materials – protect tablets from moisture and mask unpleasant flavors or odors. Two natural coatings are Zein, made from corn protein and Brazil wax made from palm trees. Watch out for “pharmaceutical glaze”, it’s actually shellac.
There are vitamin and supplement companies out there that believe in “pure encapsulation”. They use all different sized capsules for their products so have no need for fillers.
*Notes about the chart below:
  • any numbers separated by “/” represent the values for men/women. Women’s values will be in bold
  • value range for RDA or SONA: first value is for adults 19-50 and the second value is for over 50
  • the value ranges for ODI represent general health – specific conditions, you will need to reference the book to understand the high end of each range.




Fat-Soluble Vitamins (men/women)
Vitamin A (IU)




Beta-Carotene (mg)


11,000-25,000 (IU)


Vitamin D (IU)




Vitamin E (IU)




Vitamin K (mg)




Water-Soluble Vitamins (men/women)
Vitamin c (mg)




Vitamin B12 (mcg)




Folic Acid (mcg)




Niacin (mg)




Pyridoxine (B6) (mg)




Riboflavin (B2) (mg)




Thiamin (B1) (mg)




Minerals (men/women)
Boron (mg)




Calcium (mg)




Chromium (mcg)




Copper (mg)




Iodine (mcg)




Iron (mg)




Magnesium (mg)




Manganese (mg)




Phosphorous (mg)




Potassium (mg)




Selenium (mcg)




Sodium (mg)




Zinc (mg)




Eat Well, Feel Good, Have Fun

Fallon, S., & Enig, M. G. (2001). Introduction. In Nourishing Traditions. (2nd ed.). (pp. 37-47). Washington, DC: NewTren
Publishing, Inc.

Lieberman, S., & Bruning, N. (2007). The Real Vitamin and Mineral Book. (4th ed.). New York, New York: Penguin Group.

Mateljan, G. (2007). Health-Promoting Nutrients from the World’s Healthiest Foods. In The World’s Healthiest Foods. (1st ed.).
(pp. 733-804). Seattle, Washington: George Mateljan Foundation.

McGuire, M., & Beerman, K. (2011). Water-Soluble Vitamins, Fat-Soluble Vitamins, The Major Minerals, The Trace Minerals. In Nutritional Sciences: From Fundamentals to Food. (2nd ed.). (pp. 439-579). Belmont, California: Wadsworth Cengage Learning.

Ross, J. (1999). Your Master Nutritional Supplement Plan. In The Diet Cure. (1st ed.). (pp. 248-254). New York, New York: Penguin Group.


Leave a Reply

Your email address will not be published. Required fields are marked *