On a special diet? You might need to fill a few nutritional gaps. We’re here to help.
Finding a diet that works for you is a major accomplishment, whether you go gluten free, lactose free or some other kind of “free.” But with these specialized diets often comes the risk of nutritional gaps.
Everyone can use a little help from time to time to fill those gaps. With awareness and some careful planning, along with supplementation, you can avoid deficiencies that arise from restrictive special diets.
Read on to learn about just a few of the many types of special diets that prescribe avoidance of particular foods. We’ll zero in on the nutrients that may need some special attention. For each nutrient that may pose a challenge to your diet, you’ll find specific signs and symptoms that may suggest a deficiency. We’ll also provide you with some suggestions for how to fill the gap and how much of these nutrients you should aim for each day.
If you’re planning to follow a special diet, consider consulting with a health care practitioner who can advise you on how to avoid potential nutrient deficiencies and monitor you as needed.
Gluten-free diets
Gluten-free diets are essential for people with celiac disease. Celiac disease is an immune reaction to gluten, a protein in many grains. When people with celiac disease consume gluten, the resulting inflammation in their gut lining makes it harder for their body to absorb nutrients from food. Iron-deficiency anemia, as well as osteoporosis from calcium deficiency, is especially common in people with celiac disease.
A gluten-free diet can resolve symptoms of celiac disease and improve nutritional status. People who don’t have celiac disease but do have a gluten sensitivity may also find their symptoms improve on a gluten-free diet.
What you might be missing
People with celiac disease or a gluten sensitivity who are on a gluten-free diet still run the risk of nutrient deficiencies because of ongoing poor absorption or a lack of variety in their diet. Whole grains are a good source of fiber, magnesium, and B vitamins, so these nutrients and a few others need to be found elsewhere.
| You may have a deficiency in … |
Watch for these signs | Eat these foods | Get this much (supplements can help!) |
| fiber | constipation; increased cholesterol levels; weight gain; blood sugar fluctuations; tiredness | fruit; vegetables; quinoa; gluten-free grains (rice, corn, millet, buckwheat, teff); nuts; beans | 25 g/day for most women; 38 g/day for most men; 28 g/day for pregnancy |
| magnesium | loss of appetite; nausea; vomiting; fatigue; weakness; numbness; tingling; muscle cramps; abnormal heart rhythms | dark leafy greens; nuts; seeds; beans; lentils; milk; yogurt; brown rice; salmon; halibut; chicken | 320 mg/day for most women; 420 mg/day for most men; 350–400 mg/day for pregnancy |
| B vitamins | anemia; fatigue; weakness; constipation; loss of appetite; weight loss; numbness or tingling in hands and feet; balance problems; depression; confusion; soreness in mouth and tongue | gluten-free grains (rice, corn, millet, buckwheat, teff, gluten-free oats); dairy products; nuts; seeds; dark leafy greens; beans; lentils | B2 (riboflavin): 1.1 mg/d for most women; 1.3 mg/day for men; 1.4 mg/day for pregnancyB6: 1.3 mg/day for most women and men; 1.9 mg/day for pregnancyB12: 2.4 mcg/day for women and men; 2.6 mcg/day for pregnancy |
| folate | anemia; poor healing; fatigue; weakness; mouth sores; irritability; pale skin; shortness of breath | leafy greens; citrus; bananas; melons; eggs; beans; poultry; shellfish | 400 mcg DFE/day for women and men; 600 mcg DFE/day for pregnancy (see “What’s DFE?”) |
| iron | anemia; paleness; fatigue; reduced ability to exercise; frequent infections; brittle nails; decreased appetite; irritability; sore tongue or throat; thinning hair/hair loss | meat; poultry; beans; lentils; tofu; dried fruits; spinach and other dark leafy greens | 18 mg/day for most women; 8 mg/day for most men; 27 mg/day for pregnancy; more for verified deficiency and anemia |
| calcium | bone density loss and osteoporosis; muscle spasms or cramps; weak, brittle nails; numbness or tingling in hands, feet, or face; confusion; memory loss | leafy greens; beans; almonds; tofu; tahini; milk products; seafood | 1,000 mg/day for most women and men and most pregnancies |
| vitamin D | muscle pain and weakness; bone pain; immune dysfunction | fortified dairy products; fortified soy/rice/almond beverages; oily fish | 1,000 to 2,000 IU/day for most women and men |
What’s DFE?
DFE stands for “dietary folate equivalent.” The folate in food is harder for our bodies to use than the folic acid in supplements. Keep that in mind when calculating how much you need.
- 1 mcg DFE = 1 mcg food folate
- 1 mcg DFE = 0.6 mcg folic acid from fortified foods or supplements taken with food
- 1 mcg DFE = 0.5 mcg folic acid from supplements taken on an empty stomach
Athletes’ diets
Thanks to reams of research, we know that athletes and highly active people have even more reason to pay attention to their diets. High performance demands can drain body systems if they’re not adequately topped up.
What you might be missing
Healthy, varied whole food diets, along with eating frequently, cover the nutritional needs of most athletes. But athletes can run the risk of low levels in several nutrients, such as iron, magnesium, calcium, and B vitamins. Exercise enthusiasts also need to pay special attention to calorie, carb, and protein intake, as well as hydration.
| You may have a deficiency in … | Watch for these signs | Eat these foods | Get this much (supplements can help!) |
| calories | weight loss; fatigue; reduced performance; slower metabolism | healthy, nutrient-rich foods (increased intake) | 16 to 30 calories/lb body weight/day (to maintain) for active women; 17 to 23 calories/lb body weight/day (to maintain) for active men |
| hydration | weakness; fatigue; reduced performance; thirst; dizziness; muscle cramps | fluids and hydrating foods before, during, and after endurance activities (strawberries, oranges, cantaloupe, cucumber, etc.) | about 11.5 cups fluids/day for women; about 15.5 cups fluids/day for men; more when exercising |
| carbohydrates | constipation; weakness; nausea; headache; mental and physical fatigue; inability to continue endurance activity | whole grains; vegetables; honey; dried fruits | 1.4 to 4.5 g/lb body weight/day for most active women and men |
| protein | fatigue; poor healing; decreased immune function; swelling; muscle wasting; pale, dry, or flaking skin; hair breakage and loss | fish; poultry; meat; dairy; eggs; beans; nuts/nut butters; seeds; soy/soy beverages | 0.55 to 0.9 g/lb body weight/day for most active women and men |
| electrolytes | dizziness; weakness; fatigue; muscle cramps | mineral-rich foods: nuts; seeds; leafy greens; bananas | a serving of an electrolyte replacement mix or beverage |
| iron | paleness; fatigue; reduced ability to exercise; frequent infections; brittle nails; decreased appetite; irritability; sore tongue or throat; thinning hair/hair loss | meat; poultry; iron-fortified breads and cereals; beans; lentils; tofu; dried fruits; spinach and other dark leafy greens | 18 mg/day for most women; 8 mg/day for most men; more for documented deficiency and anemia and for some female athletes |
| essential fatty acids | fatigue; dry skin/mouth/eyes/hair; poor wound healing; depression | nuts; seeds; beans; coldwater fish | at least 1.1 g/day for women; 1.6 g/day for men |
| magnesium | fatigue; muscle pain; restlessness; anxiety; sleep problems; abnormal heart rate | dark leafy greens; nuts; seeds; beans; lentils; milk; yogurt; brown rice; salmon; halibut; chicken | 320 mg/day for most women; 420 mg/day for most men |
| B vitamins | anemia; fatigue; weakness; constipation; loss of appetite; weight loss; numbness or tingling in hands and feet; balance problems; depression; confusion; soreness in mouth and tongue | whole grains; dairy products; nuts; seeds; dark leafy greens; beans; lentils | B-complex supplement daily |
| calcium | bone density loss; muscle spasms; cramps; weak, brittle nails; numbness or tingling in hands, feet, and face; confusion; memory loss | leafy greens; beans; almonds; tofu; tahini; dairy products; fish and seafood | 1,000 mg/day for most women and men |
Lactose-free diets
Lactose is a sugar in milk and milk products that causes problems for people whose bodies don’t have enough lactase, an enzyme needed to digest lactose. Lactose-intolerant people can experience symptoms such as gas, bloating, diarrhea, and other gastrointestinal upset after eating foods that contain lactose, so they often opt for lactose-free diets.
What you might be missing
Although all nutrients available in milk products can be easily sourced from other foods, if you avoid lactose, special attention should be paid to calcium and vitamin D and B12 sources.
| You may have a deficiency in … | Watch for these signs | Eat these foods | Get this much (supplements can help!) |
| calcium | bone density loss, muscle spasms | leafy greens; almonds; tofu; tahini; sardines/salmon with bones | 1,000 mg/day for most women and men and most pregnancies |
| vitamin D | muscle pain and weakness; bone pain; immune dysfunction | fortified soy/rice/almond beverages; oily fish; egg yolks | 1,000 to 2,000 IU/day for most women and men |
| vitamin B12 | anemia; fatigue; weakness; constipation; loss of appetite; weight loss; numbness or tingling in hands and feet; difficulty maintaining balance; depression; confusion; soreness of mouth or tongue | B12-fortified cereals; fortified soy products; fortified coconut/rice/oat/almond milk; nutritional yeast; meat; poultry; fish and seafood | 2.4 mcg/day for women and men; 2.6 mcg/day for pregnancy |
Special diets: the data
- Approximately 1 percent of Americans suffer from celiac disease, while an estimated 20 million Americans are gluten sensitive.
- The B vitamins are a family of eight vitamins that are essential for turning our food into fuel. Those with celiac disease may have trouble absorbing B vitamins (among other nutrients).
- Eighty-five percent of Americans with celiac disease don’t know they have it, and the average patient waits more than four years for an official diagnosis.
- According to an extensive study published in 2018, athletes focusing on leanness—such as endurance athletes—may be at risk of energy deficiency and serious health conditions, including eating disorders, premature osteoporosis, and increased cardiovascular risks.
- Regularly eating fewer calories than your body’s daily requirement may slow down your metabolism.
- Approximately 65 percent of people worldwide have a reduced ability to digest lactose after infancy.
