s3/e04 Micronutrients for Runners with Kirsten Screen, MPH, RD, LD (@screennutrition)

Magnesium

Magnesium plays a pivotal role in over 500 enzymatic reactions in the body, making it essential for athletic performance and overall health. Kirsten Screen emphasizes that many people are deficient in magnesium due to poor dietary variety and depleted soil nutrients 1. She suggests focusing on a diverse diet rich in green leafy vegetables, nuts, seeds, and dairy to meet magnesium needs naturally 2.

Your body knows what to do when it gets it in whole food form.

--- Kirsten Screen

While supplementation can be beneficial, Kirsten advises against excessive intake, as the body efficiently eliminates excess minerals 2.

   

Iron

Iron is often misunderstood, with many assuming deficiencies when the real issue lies in its transport within the body. Kirsten Screen explains that iron is recycled efficiently, and deficiencies often stem from problems in moving iron to where it's needed, rather than a lack of iron itself 3. This transport is facilitated by magnesium, copper, and vitamin A, highlighting the interconnectedness of micronutrients 3.

We have plenty of total iron. We just can't move it.

--- Kirsten Screen

Symptoms like fatigue can often be misinterpreted, leading athletes to overlook underlying issues until performance is affected 4.

   

Vitamin D

Vitamin D is crucial for health, but its deficiency is common due to limited dietary sources and inadequate sun exposure. Kirsten Screen advises against excessive supplementation, as it can disrupt iron transport and lead to other health issues 5. Instead, she recommends moderate sun exposure to naturally boost vitamin D levels 5.

We are designed the way we are because we can literally make an active hormone from the sun.

--- Kirsten Screen

Understanding the storage nature of fat-soluble vitamins like vitamin D is vital, as excessive intake can lead to toxicity 6.