Nutrient Deficiencies at High Altitudes

I am currently spending a couple of weeks in the mountains at altitude of 9,000 feet, higher during hikes, which prompted me to write this article.

Family hiking in the mountains at high altitude.

High altitudes reduce oxygen availability and increase metabolic demands. This combination can lead to specific nutrient deficiencies. Being at high altitude - above 8,200 feet (2,500 meters) - for a week or more can lead to deficiencies if precautions aren’t taken. In addition, increased caloric and fluid needs are vital due to increased metabolism and to avoid dehydration. This is especially important if planning backpacking, trekking, hunting, mountain or ice climbing trips, or any mountainous excursions requiring high activity levels or extended stays.

Nutrient deficiencies include:

Iron - Being at altitude stimulates red blood cell production to carry oxygen which uses iron. Thus, iron stores can become depleted if not replenished.

Vitamin D - If time outdoors is limited, it can affect vitamin D levels, which in turn affects bone health.

B vitamins - Due to increased metabolic demands, B vitamins, primarily B12 and folate, can become depleted.

Best Dietary Strategies

High altitude affects your digestive system, leading to constipation, diarrhea, bloating, and increased gas. It can affect how you digest foods, so here are some tips on what to do, what to eat, and what to avoid.

1. Hydration, hydration, hydration - staying adequately hydrated with mostly water helps to prevent altitude sickness and dehydration. Realize that caffeine and alcohol can be dehydrating and act as a diuretic. The lower oxygen levels at altitude can amplify the effects of alcohol. Water is best and can be flavored with electrolyte packets, especially if trekking. Aim for 2-3 liters daily, more depending on exertion.

Woman hiker hydrating with water, the most important fluid for the mountains.

An easy sign to watch is the color of your urine. To know you are well-hydrated, your urine should look like water or lemonade, not dark yellow.

2. Carbohydrates - focus primarily on complex carbohydrates from whole grains, vegetables, and fruit. These can be easier on the gut and provide energy. Fruit is also a liquid source.

Included are oats, quinoa, brown rice, sweet potatoes, beans, peas, and lentils. Water-dense fruits include watermelon, strawberries, and oranges.

A variety of healthy foods such as fruit, vegetables, seafood, nuts, and legumes which provide protein, complex carbs, healthy fats and antioxidants.

3. Iron-rich foods - since iron deficiency is one of the nutrient deficiencies seen at higher altitudes, incorporating iron-rich foods is vital. These include dark, leafy greens, lean meats, poultry, seafood, beans, and lentils.

4. Lean proteins - many lean protein options also provide iron. Stick with low-fat options since a higher fat content slows digestion. 

Lean protein options include lean meats, skinless chicken and turkey, fish, eggs, Greek yogurt, cottage cheese, beans, lentils, peas, and tofu. Choose from both animal- and plant-based options.

5. Antioxidant foods - these foods are also anti-inflammatory and good to consume before and during time at altitude. These include berries, oranges, mandarins, grapefruit, leafy greens, beans, beets, and artichokes.

6. Potassium-rich foods - bananas, potatoes, sweet potatoes, tomato sauce, Swiss chard, avocado, beans (black and white varieties), lentils, dried apricots, and Medjool dates all fit the bill.

What to Avoid

1. Excess salt - although you do need some salt, avoid very salty foods like fast food, chips, crackers, canned soups, and dried meats. The high salt content can lead to dehydration.

A wooden spoon filled with caffeine beans and a spoon of salt. These can both be hydrating in the mountains and should be minimized.

2. Caffeine - as mentioned before, caffeine acts as a diuretic and can contribute to dehydration. Rather than coffee, consider herbal teas and cocoa for hot drink options and skip the colas and energy drinks. After a caffeinated drink, follow up with a full cup of water. 

3. Fatty meals and foods -  rather than fried foods, fatty protein, and full-fat dairy, choose low-fat options and cooking methods instead.

4. Ultra-processed foods - these are typically high in fat and sugar, both of which can affect digestion and lead to sugar crashes. By the way…these foods aren’t good for you at any altitude! 

5. Spicy foods - these may exacerbate any digestive issues (altitude-related or not).

The above are general guidelines to help you feel best for a high-altitude vacation or mountain trek or, if you live at altitude, to help prevent nutrient deficiencies. These tips, especially hydration, should begin a week or two before departure. Stay hydrated, eat for energy, stay well.