🕵️‍♀️ Deficiency Detective: 69 Year Old Vegan With Muscle Cramps And Dry Skin
Clinical Vignette:
Meet Lina, a 69-year-old vegan who’s been following a plant-based diet for over a decade. She’s generally healthy and has no surgical history but is on Levothyroxine. She’s always been health-conscious, stays active, and makes an effort to eat balanced meals. But recently, some strange symptoms have started to crop up.
Lina’s been experiencing stiff, achy muscles, especially in her legs and back, and she’s noticed that her skin seems drier than usual. Her fingernails have become brittle, and her hair feels coarser. Lately, she’s also felt a peculiar tingling in her lips and fingers. And if that wasn’t enough, she’s had muscle cramps at night that make it tough to get restful sleep. These symptoms have been making her feel not only physically off but mentally drained, with bouts of confusion and some foggy forgetfulness creeping in.
👩⚕️ Her PA wants to investigate further and has ordered some blood work, suspecting a nutrient deficiency.
Which nutrient might Lina be missing in her diet?
Hint: Over time, a deficiency in this nutrient can affect the brain and cause neurologic or psychologic symptoms, such as confusion, memory loss, delirium, depression, and hallucinations.
Answer: Calcium!
What is Calcium?
Calcium is the most abundant mineral in the body and plays a vital role in many bodily functions, from forming and maintaining strong bones and teeth to supporting muscle contractions, nerve transmission, and vascular functions. Approximately 99% of the body's calcium is stored in bones and teeth, with the remaining 1% is in blood, muscle, and other tissues where it aids in cellular functions.
Symptoms of Calcium Deficiency
A calcium deficiency, or hypocalcemia, can range from asymptomatic to severe complications depending on the extent and duration of the deficiency. Early symptoms may include:
- Muscle cramps and spasms, particularly in the back and legs
- Tingling or numbness in the lips, fingers, and feet
- Stiff and achy muscles, as well as muscle spasms
- Dry, scaly skin, brittle nails, and coarse hair
- Neurological symptoms in advanced deficiency, including confusion, depression, forgetfulness, paresthesia, seizures and, in severe cases, hallucinations or delirium
Long-term calcium deficiency can lead to more serious complications such as rickets, osteoporosis, osteomalacia and an increased risk of fractures due to decreased bone density.
Risk Factors for Calcium Deficiency
Several factors may predispose individuals to calcium deficiency, including:
- Age: Older adults have an increased risk due to decreased bone density and lower calcium absorption rates.
- Menopause: Women undergoing menopause experience a decrease in estrogen, which is essential for calcium absorption, and an increase in urinary calcium placing them at a higher risk. On average, women lose approximately 1% of their bone mineral density (BMD) per year after menopause.
- Dietary Restrictions: Vegetarians and vegans, especially those who do not consume dairy products, may not get enough calcium in their diets.
- Lactose Intolerance: Individuals who avoid dairy due to lactose intolerance often struggle to meet daily calcium needs.
- Certain Medical Conditions: Conditions such as Crohn’s disease, celiac disease, and kidney disease can impair calcium absorption.
- Medications: Several medications can interfere with calcium absorption, notably are PPIs, iron supplements, thyroid hormones, beta-blockers and diuretics.
Notice our patient, Lina's risk factors: is an older female in menopause, who follows a vegan diet and is taking thyroid hormone.
Hypocalcemia can also be a result of a vitamin D or magnesium deficiency, impaired parathyroid hormone production leading to hypoparathyroidism, impaired bone resorption of calcium, critical illness, or use of certain medications (e.g., bisphosphonates, cisplatin, or proton pump inhibitors)
Dietary Source of Calcium
For patients following plant-based diets, calcium can still be sourced effectively through certain foods and fortified products. Here are some high-calcium options:
- Fortified Plant-Based Milks: Many almond, soy, oat, pea, cashew and rice milks are fortified with calcium and provide comparable amounts to dairy milk (~300mg). Encourage your patient to review the Nutrition Facts labels for added sugars. Pro Tip: Shake the container well before using it as the calcium often settles.
- Leafy Green Vegetables: Collard greens, turnip greens, bok choy, and kale offer calcium, though with slightly lower bioavailability than dairy (~100mg).
- Fortified Cereals and Juices: These can be excellent sources of calcium, especially for individuals with limited dietary diversity. (OJ ~350mg and cereal ~130mg)
- Tofu and Tempeh: Some tofu, particularly varieties made with calcium sulfate, can contain as much as 200 mg per serving.
- Nuts and Seeds: Almonds, chia seeds (~75mg), and sesame seeds contribute to calcium intake but may need to be consumed in larger amounts.
- Pescatarian/flexitarians: Canned sardines and salmon with bones are good sources (~325mg).
A Note About Calcium Bioavailability
Calcium absorption can vary significantly depending on the food source. For example, calcium from dairy products and fortified foods is absorbed at about 30%. By contrast, certain plant compounds like oxalates (found in spinach, beet greens, Swiss chard, and rhubarb) and phytates (found in legumes and grains) can bind with calcium, forming insoluble salts that decrease its absorption. As a result, calcium absorption from spinach, for instance, is only about 5%, compared to 27% from milk.
Some leafy greens, however, are low in oxalates, making their calcium more bioavailable. Kale, turnip greens, and mustard greens have absorption rates closer to those of dairy, even though their overall calcium content per serving is lower. Other cruciferous vegetables, such as broccoli and cabbage, also provide calcium with similar bioavailability to milk.
All that to say, don’t confuse your patient or hyper-focus on “low oxalate” foods. Instead, encourage them to focus on getting calcium from a wide variety of foods—it’s the best way to help them meet their needs.
Treatment for Calcium Deficiency
The treatment for calcium deficiency generally involves dietary adjustments to increase intake of calcium-rich foods or calcium supplements if necessary. For adults, the Recommended Dietary Allowance (RDA) is:
- 1,000 mg per day for men and women aged 19-50
- 1,200 mg per day for women aged 51 and older and men aged 71 and older
In cases where dietary changes are insufficient, consider recommending a calcium supplement, preferably calcium citrate or calcium carbonate.
Patient Education Recommendations for Healthcare Providers
Educating patients on the importance of calcium can be crucial in preventing deficiency and promoting long-term health. Here are some actionable tips for patient education:
- Highlight the Importance of Consistency: Calcium should be consumed throughout the day, as the body absorbs it more efficiently in smaller, consistent amounts.
- Emphasize Diverse Sources: Reinforce the idea that while dairy is a good source, there are many plant-based alternatives that can meet calcium needs.
- Discuss Supplement Options: Help patients understand when a supplement may be necessary, how to take it effectively, and the recommended dosage for their age and lifestyle.
- Encourage Weight-Bearing Exercise: For older adults and those at risk of osteoporosis, weight-bearing exercise can help build and maintain bone density.
- Monitor for Medication Interactions: Calcium can interact with several medications, potentially lowering calcium absorption or affecting drug efficacy. Be especially mindful with patients taking dolutegravir, levothyroxine, lithium, or quinolone antibiotics (such as ciprofloxacin, gemifloxacin, and moxifloxacin). For patients on these or similar medications, it's essential to discuss calcium status and assess whether additional monitoring or adjustments are needed to support optimal levels and prevent deficiency.
Helping patients understand the sources and importance of calcium is key, particularly for those on plant-based diets who may struggle with adequate intake. By tailoring advice to dietary preferences, healthcare providers can offer personalized care that supports overall health and helps prevent the long-term consequences of calcium deficiency.
Resources:
https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
Colleen Sloan
PA-C, RDN and Founder of Exam Room Nutrition
Colleen Sloan received her Masters of Medical Science from Nova Southeastern University and has been a practicing Pediatric PA since 2017. Prior to going to PA school, she worked as a Registered Dietitian helping patients on their weight loss journey. Her goal with Exam Room Nutrition podcast is to bridge the gap between medicine and nutrition. She loves animals, a good cup of coffee and reading books with her 14 year old daughter.
