In the world of nutrition research, we are still trying to figure out how nutrients are absorbed from our foods and how to get the most out of every meal for long term health and longevity. What we have learned is, in many instances nutrients are better absorbed - or, more bioavailable - from foods than from dietary supplements. The hundreds of thousands of natural chemical reactions in our foods appear to be working synergistically throughout our digestion and absorption process.
We have found that there are a couple good guidelines to follow to when maximizing nutrient intake from the foods we eat. Read on to see how many you’ve already heard about!
- Get a side of citrus with your iron.
Iron is a mineral used in our bodies for oxygen transport and for energy metabolism. Scientific research demonstrates that we typically absorb iron from animal-based sources (poultry, fish, eggs, beef) easier than plant-based sources (dark greens, beans, tofu, and whole grains). What we’ve learned is that citrus foods - high in vitamin C - enhance iron absorption, so pairing the high-iron foods above with citrus like tomato, lemon, lime, mango, grapefruit, orange, or pineapple may help you get closer to your 18 mg RDA for iron (27 mg if you’re pregnant, and 8 mg if you’re over 50.)
Recommendation: Aim to pair citrus with your iron sources 1-2 times per day to optimize your iron intake.
- Calcium has some road blocks.
Low calcium intake is something many Americans struggle with. High calcium sources include dairy foods like milk, fortified milk substitutes, yogurt, cheese, cottage cheese, and yes - sometimes even ice cream or frozen yogurt. Check your nutrition labels - anything that provides at least 20% of your daily value of calcium is considered an excellent source. Vegan choices include tofu, dark leafys like collards and swiss chard, molasses, and edamame.
Increasing intake of these foods will help get enough calcium into your diet, but there are a couple things to know about maximizing your absorption. First, some minerals can actually bind to calcium and force them to be excreted from the body during digestion, without ever getting absorbed. These include oxalate, phosphorus, and insoluble fiber, mostly found in veggies. Second, anything that speeds up the process of urine production (mostly high amounts of salt and caffeine) will also lead to more calcium being excreted before it gets utilized by the cells.
Vitamin D has actually been found to be helpful in absorbing higher amounts of calcium, which is why they are often paired together in dietary supplements. Food sources of vitamin D include fish (like tuna and salmon), egg yolks, cheese, and fortified milk and juice products.
Recommendation: For enhanced absorption enjoy high calcium foods separately from veggies, salt, or caffeine and pair with high vitamin D sources like whole eggs and fortified products.
- Oil up.
Fun fact: some of the vitamins and antioxidants we get from plant foods (such as vitamins A, D, E, and K) are fat-soluble. This means they don’t interact well with water and need to be surrounded by fat molecules to be absorbed into the body. This is where we add in our healthy fats: avocado, nuts, seeds, and plant-based oils such as olive, canola, or walnut. Be cautious of the low-fat dressing in this case -- if there are less than 50 calories per serving there may be very little oil in the product to recruit for absorption duty.
Recommendation: Enjoy your salads and veggie sides with a drizzle of oil, a cupped palm full of nuts, or ⅓ of an avocado for to optimize your vitamin and antioxidant intake.