I know I won’t shock anyone when I say that we Americans can be extreme at times – we tend to think that if a little is good, a lot must be better! And no area is a better example of this than the world of vitamins. Why get 100% of your daily value of vitamin C if you can have 150%? Or 200%? Or even 5,000%? In fact, there is such a thing as too much of a good thing, and every vitamin and mineral has a “TUL” (tolerable upper limit) value – the point at which the benefits max out, and beyond which there can be adverse events. On the opposite end of the spectrum are the minimum levels we need to consume to prevent deficiency. Too little vitamin D leads to weak bones and rickets. Too little vitamin C, and you get scurvy.

Most deficiency diseases have been eradicated in our country, thanks to better child nutrition, a stable and diverse food supply, improved testing, and supplementation. But if you’re asking the right question, you’re wondering: isn’t there a pretty big difference between not just preventing disease, but thriving? And the answer is a resounding YES. How much you need of various nutrients changes over the course and stage of your life, increases when you’re sick, doing strenuous exercise, or stressed, and differs based on gender and genetics. You can assess the range you need by putting in your stats here, or get lab work done if you want to take a deep dive. Some nutrients are more likely to be an issue than others. Here’s a quick glance at few.

Potassium

Most prominent in fresh fruits and vegetables, it’s no wonder why we’re lacking in this one…most people just don’t eat enough! There is more potassium than sodium in every single piece of uncooked produce on earth, but we tend to reverse that ratio in preparation of food. More and more research points to that potassium to sodium ratio as being the true issue in hypertension and cardiovascular health, which is why we need to focus on both nutrients (not just the typically thought of sodium number). You probably tend to think about bananas for potassium, but there are lots of foods we commonly eat that are higher – sweet and white potatoes, tomato sauce, and watermelon all leave bananas in the dust.

Vitamin D

Yup, your body can make this one…if you get enough sun! It’s harder to get enough if you live above or below certain latitudes, especially in winter, and especially if you have darker skin. Not many foods contain it naturally – wild caught fatty fish, pastured eggs to a small degree, irradiated mushrooms – so this is one for which you should get tested and consider a supplement. As much as two thirds of the population could be at risk of having low levels, and while most aren’t low enough to develop rickets, studies link it to everything from heart disease to asthma. The grey area is big here!

Iron

Most iron stores are found in our blood, which makes women of child-bearing age the most susceptible to being at risk of low levels, especially if they’re vegetarian. Iron is best absorbed from animal meat sources because it’s already in the form our bodies need and not hindered by plant “anti-nutrients” that block absorption. However, its absorption is greatly enhanced by Vitamin C to help unlock it from sources like beans and spinach, and supplementation is easy and inexpensive! Low iron levels can cause fatigue and lethargy, making it a problem you’ll definitely notice but might not attribute to nutrition. Basically, if you’re a woman between the ages of 12 and 50 (especially if you exercise intensively or frequently), this is something you should ask your doctor about!

Vitamin A

When you think vitamin A, think about the color orange (sweet potatoes, pumpkin, carrots) and dark leafy greens. It’s fat soluble, which means it’s best absorbed in the presence of a meal that contains fat. Vitamin A is also one instance where supplementation could be a problem. Studies that attempted to prevent cancer in high-risk populations actually seemed to have the same or higher incidence of cancer when taking Vitamin A.

Fiber

I know, fiber isn’t a vitamin or mineral. And it’s almost the opposite because it acts by not being absorbed instead of requiring breakdown and uptake. But here in America, despite the fact that we overconsume food, we aren’t getting enough of the types of food that contain fiber – or are eating versions of foods that have it eliminated (refined grains & juices, I’m looking at you!) Most Americans get around 12-15g a day, and the minimum recommendation (for small women, not all people!) is 25g. Reconsider your sandwich bread, pasta, cereal, and rice – choose 100% whole grain versions of those products when possible, have a serving of nuts or seeds daily, and of course eat your fruits and veggies! Getting to 25g is really easy with just a few swaps and additions.

So, when it comes to getting the levels of vitamins and minerals, look to your foods first (you’ll almost never to be able to reach toxic upper limits this way!) and supplement based on your individual needs – ideally with some lab work to back up your choices! And don’t forget to check out the nutrition facts on your V+B meals – because they’re made with nutrient dense ingredients, the vitamin and mineral levels are high and the portions are satisfying.

Sarah Waybright MS, RD is the owner and founder of WhyFoodWorks and the team dietitian for Vegetable and Butcher. WhyFoodWorks does nutrition education through food in Washington, DC in corporate seminars. Vegetable and Butcher is a subscription-based service that delivers chef designed, dietitian approved, thoughtful prepared meals to health-conscious people in Washington, DC. You can find Sarah on Twitter, Facebook, Pinterest or Instagram to get food and nutrition tips - and of course, healthy recipes.