Why is my potassium and other minerals so low?

  • 4 Minutes Read

It’s a hidden problem with all nutrient trackers: missing values. And when the value for a nutrient is missing for a food you eat, your calculated intake for that nutrient is lower than it should be. Why is this happening?

Why is my potassium and other minerals so low?

You faithfully measure and track your food intake in the MyNetDiary system. You’re picking a really healthy diet, with lots of vegetables, fruit and whole grains. You expect the nutrient intake results to be stellar. But, wait. Why is the potassium so low? Why is copper so low? Biotin? Vitamin K? Even omega-3 fats?

No, these results don’t necessarily mean you should start taking supplements. The low values are more likely due to a common but little-known problem shared by all calorie trackers: incomplete data. Accurate values for all nutrients for all possible foods are not available. And if they’re not available, that field in the database for that nutrient for a particular food is blank or zero. Even if in reality it’s a significant number.

Why Isn’t My Potassium Higher?

Let’s say you buy lots of fruit and vegetable smoothies, made by a national beverage company. Vegetables and fruit are known to be excellent sources of potassium, among other nutrients. But food companies are not required to list potassium on food labels. And since they aren’t required to list that, they don’t bother to analyze or calculate the potassium values for their smoothies. When you enter the smoothie in your calorie tracker, potassium comes up as blank or zero, even though it might actually be 400 mg. If that happens enough times in your daily food diary, your potassium total will be lower than your actual intake. How much lower? We don’t know. It depends on how many manufactured foods you consume.

The issue of commercially manufactured foods is key. The USDA maintains a database of nutrient values for foods, which is used as the basis for all commercial food trackers. In the case of standard foods (an apple, ground beef, sliced bread, etc.) the values are based on chemical analysis of that food. But, if no analysis was done for a particular nutrient, there will be no listing. Take “Orange juice, chilled, includes from concentrate” (yes, that’s an actual listing). The basic report includes 33 nutrients. The full report includes 114.* Let’s look at a brand name: Ocean Spray 100% Orange Juice. The list is only 9 nutrients long, limited to the nutrients required on the nutrition facts panel. If you use that listing for your morning orange juice, you’ll be missing values for lots of key nutrients.

Why No Data?

Why don’t the food companies provide more complete data? They don’t have to. They are only required to provide nutrient data for the handful of nutrients that must be listed on the nutrition facts panel. Plus these analyses are expensive. And every time the company changes their product formulations, they have to go through the expense of re-analyzing the product.

When it comes to data in systems like MyNetDiary, you start to see the magnitude of the issue. The USDA database contains information on 184,000 foods, and many of the listings sound like nit-picky duplicates of each other. For example, when you search “orange juice” you get dozens of listings, some standard unbranded variations, many branded products. How different can they be from each other? Meanwhile MyNetDiary has a database of over 732,000 foods, many entered by users, with data imported from a nutrition facts panel. Which means missing data on many nutrients. This is not anyone’s fault; it’s just the state of affairs in the nutrient database business. By the way, you can hide foods entered by other members (which are often less accurate have more missing data) by going into your Settings and toggling off “contributed items.”

So What Is Accurate?

At the moment, the most accurate values for your food diary will be for those few nutrients required on the nutrition facts panel, including:
Dietary Fiber
Vitamin A
Vitamin C

When listed, vitamins and minerals are displayed as a % Daily Value (%DV). When a member enters information for a commercial food, MyNetDiary uses the %DV entry and converts it to the actual value for that nutrient.

So if you consume lots of commercially manufactured foods, the values for your food diary analysis might come out too low for some nutrients. Potassium, B6, copper, zinc, biotin, magnesium, vitamin E, omega-3 fats and vitamin K are just some examples.

The best way to get better data is to eat mostly unprocessed whole foods that are likely to have more complete data from the USDA database. If you prepare recipes using those types of foods, your recipe data will also be more complete. If you’re OK not knowing exact numbers, you can just focus on foods that are known to be good sources of all those missing nutrients, even if those foods are commercially manufactured or restaurant foods. If you like a particular brand of hummus or vegetable soup or smoked salmon or canola-oil salad dressing, you’ll still be getting the vitamins, minerals, and/or omega-3 fats present in garbanzo beans and sesame butter or greens and carrots or salmon or salad dressing even if the manufacturer didn’t provide numbers for those nutrients.

Potassium is coming!

If you’re trying to track your potassium intake, there is one bright spot on the horizon. New food labeling regulations will require a potassium listing on the label starting next year (July 2018), which means more accurate values for potassium will show up in databases for more foods. Some companies are already including it on labels. Added sugars will also be listed separately from Total Sugars.


At the moment, unless you have access to a food chemistry lab, and are willing to spend the money to analyze all your food, no food tracking system will give you 100% complete and accurate data for all known nutrients. You’ll get the most complete data by eating an unprocessed diet, tracking only foods that have values for all nutrients. This is probably unrealistic for most people, especially if you eat many commercially prepared packaged foods or restaurant foods. One simple solution: a balanced diet focused on vegetables, fruits, nuts, lean meats, dairy foods and whole grains will cover your intake of many vitamins and minerals not listed on Nutrition Facts Panels. A monotonous diet of cheeseburgers, soft drinks, cheese pizza and chips will not, regardless of whether a nutrient database contains complete data for these foods.

*NOTE: the USDA National Nutrient Database defines “nutrient” rather generously - it includes everything a food can be analyzed for, such as caffeine, many isoflavones, ethyl alcohol and individual amino acids.

Nutrients->Potassium Tracking & MyNetDiary->Tracking Tips
Jan 24, 2017
Donna P Feldman MS RDN is author of Food Wisdom for Women and "Feed Your Vegetarian Teen". She writes about food and nutrition at Radio Nutrition.

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