How Is Calcium Used in the Body?
Most of the calcium in your body—98%—is stored in your bones, and about 1% is in your teeth. The rest of the calcium plays a crucial but lesser-known role in cell-to-cell communication. Calcium ions (Ca++) help brain cells release neurotransmitters and assist muscle cells in contracting. The importance of calcium to your overall health cannot be overstated.
What Is Calcium Deficiency?
Calcium deficiency, also known as hypocalcemia, occurs when your blood calcium levels are too low. Calcium insufficiency, on the other hand, means you aren’t getting the recommended daily intake of calcium, as set by health organizations like the Food and Nutrition Board (FNB) of the Institute of Medicine in the United States. Calcium deficiency is more severe than insufficiency and affects various groups, including the elderly, pre-teens, teenagers, vegans, overweight individuals, and those from low-income households.
Calcium deficiency is rarely due to a lack of dietary calcium alone. It’s more likely caused by medical conditions that impair calcium absorption from foods or supplements.
Hypocalcemia Causes
Certain medical conditions can lead to calcium deficiency, including:
– Kidney failure
– Surgical removal of the stomach or parathyroid gland
– Hypoparathyroidism
– Pancreatitis
– Massive blood transfusions
– Septic shock
– Hormonal changes, especially in women
– Vitamin D deficiency
Several medications can also increase the risk of calcium deficiency, such as:
– Diuretics
– Drugs for elevated calcium levels
– Anticonvulsants like phenytoin and phenobarbital
– Certain chemotherapy drugs
– Corticosteroids
Calcium Deficiency Symptoms
When your body is deficient in calcium, it can lead to other medical conditions, notably osteopenia and osteoporosis. Osteopenia is characterized by low bone mineral density and can progress to osteoporosis, where bones become so porous that they easily fracture during everyday activities. Osteoporosis significantly affects women more than men, causing millions of bone fractures annually and leading to the hunched backs seen in some older adults.
Calcium deficiency can cause the body to draw calcium from bones to maintain essential functions in the brain, heart, nervous system, skin, and muscles. Symptoms of calcium deficiency include:
– Weak or brittle nails
– Reduced grip strength
– Numbness and tingling in the fingers
– Muscle cramps
– Lethargy and fatigue
– Poor appetite
– Abnormal heart rhythms
– Stooped or hunched posture
Calcium Deficiency & the Cardiovascular System
The National Center for Geriatrics and Gerontology has found that calcium deficiency can harm both bone and cardiovascular health. Research from Osaka University Medical School indicates that calcium deficiency may contribute to high blood pressure.
Calcium Deficiency & Brain Health
Studies have linked calcium deficiency to Alzheimer’s disease. Increasing calcium and vitamin D intake may reduce some risks associated with Alzheimer’s. Deficient calcium levels have also been observed in adults with anxiety and headaches. Since calcium is vital for memory and cognition, maintaining adequate calcium levels is crucial for brain health.
Groups at Risk of Calcium Deficiency
Certain groups are more susceptible to calcium deficiency and should monitor their intake closely:
Post-Menopausal Women & Older Adults
After menopause, women experience a decrease in estrogen levels, which reduces calcium absorption in bones. This can result in significant bone mass loss. Consuming calcium-rich foods and taking calcium and vitamin D supplements can help. While age-related bone loss is more pronounced in women, all older adults should monitor their calcium intake. Older women are also at risk of exceeding the recommended calcium intake from diet and supplements, which can be harmful.
Amenorrheic Women (without menstruation)
Women who lose body fat to the point of ceasing menstruation, such as athletes or those with eating disorders like anorexia nervosa, have lower calcium absorption and increased calcium excretion, leading to a higher risk of stress fractures.
Vegans & Vegetarians
Vegans, who avoid all animal products, are at higher risk of calcium deficiency due to the lack of dairy in their diet. Vegetarians also have a slightly higher risk compared to those who consume both meat and dairy.
Low-Income Households
Data shows that low-income individuals in the United States have a higher risk of calcium insufficiency. Surveys from 2001 to 2010 revealed that calcium intake increases with income.
Teenagers
Boys and girls aged 9-13 and girls aged 14-18 are at higher risk of calcium insufficiency due to their growing skeletons. They should ensure they get enough calcium through diet or supplements.
Overweight Individuals
Overweight and obese individuals often have lower calcium intake compared to their non-overweight counterparts, though dietary supplementation with calcium does not necessarily lead to weight loss.
People With Digestive Conditions
Conditions like celiac disease and inflammatory bowel disease (IBD) can impair nutrient absorption, including calcium and vitamin D. This can lead to lower bone density, and supplementation may be necessary.
How to Counteract Calcium Deficiency
To reduce the risk of calcium deficiency, adopt a healthy lifestyle that promotes overall health. This includes a plant-based diet rich in organic fruits, vegetables, nuts, and seeds. If you consume dairy, choose organic, pasture-raised options. Staying fit, reducing stress, and avoiding toxins are also important.
If you’re at higher risk for hypocalcemia, monitor your calcium intake and occasionally have your blood calcium levels tested. Increase consumption of calcium-rich foods and take supplements if needed. If diagnosed with hypocalcemia, treatments may include hormone supplements, medications to increase calcium absorption, and vitamin D and calcium supplements. Be aware of medication side effects and choose high-quality supplements.
Recommended Calcium Intake
The Food and Nutrition Board at the Institute of Medicine recommends the following daily calcium intake:
| Age | Male | Female | Pregnant | Lactating |
|---|---|---|---|---|
| 0 – 6 months* | 200 mg | 200 mg | N/A | N/A |
| 7 – 12 months* | 260 mg | 260 mg | N/A | N/A |
| 1 – 3 years | 700 mg | 700 mg | N/A | N/A |
| 4 – 8 years | 1,000 mg | 1,000 mg | N/A | N/A |
| 9 – 13 years | 1,300 mg | 1,300 mg | N/A | N/A |
| 14 – 18 years | 1,300 mg | 1,300 mg | 1,300 mg | 1,300 mg |
| 19 – 50 years | 1,000 mg | 1,000 mg | 1,000 mg | 1,000 mg |
| 51 – 70 years | 1,000 mg | 1,200 mg | N/A | N/A |
| 71+ years | 1,200 mg | 1,200 mg | N/A | N/A |
Foods High in Calcium
When thinking of calcium-rich foods, dairy is often the first that comes to mind, but many vegetables are also excellent sources. The following table lists foods high in calcium to help you boost your intake:
| Food | Mg Per Serving | % Daily Value (For an Adult) |
|---|---|---|
| Plain Yogurt (8 oz) | 415 mg | 42% |
| Cheddar cheese (1.5 oz) | 307 mg | 31% |
| Milk (2%) | 293 mg | 29% |
| Firm Tofu (fortified) | 253 mg | 25% |
| Salmon (3 oz canned) | 181 mg | 18% |
| Chia seeds (? cup) | 130 mg | 13% |
| Turnip greens (? cup) | 99 mg | 10% |
| Kale, cooked (1 cup) | 94 mg | 9% |
| Sesame seeds (1 tbsp) | 88 mg | 9% |
| Orange (1 whole) | 28 mg | 3% |
| Kale, raw (1 cup) | 24 mg | 2% |
Calcium Supplements
If your diet lacks sufficient calcium, or if you are at higher risk of deficiency, taking a calcium supplement can help meet your needs. Consult your healthcare provider to determine the appropriate supplement and dosage for your situation.
Types of Supplements
Calcium supplements come in various forms, including:
– Calcium orotate
– Calcium carbonate
– Calcium citrate
Calcium orotate offers the highest bioavailability. Calcium carbonate, which is similar to chalk, has the lowest absorption rate and must be taken with food. Calcium citrate is better absorbed and does not require food for absorption. Research by German physician Hans Nieper found that calcium orotate crosses cell membranes, providing the highest bioavailability.
Calcium Side Effects & Safety Precautions
Taking too much calcium can pose health risks. Studies link excess calcium supplementation to cardiovascular issues, possibly due to low absorption of certain supplements. Calcium can interfere with the absorption of minerals like iron, zinc, and magnesium, so it is best taken between meals. This makes calcium orotate or citrate preferable to calcium carbonate, which requires food for absorption.
The following table lists the upper intake levels of calcium according to the Food and Nutrition Board:
| Age | Male | Female | Pregnant | Lactating |
|---|---|---|---|---|
| 0 – 6 months | 1,000 mg | 1,000 mg | N/A | N/A |
| 7 – 12 months | 1,500 mg | 1,500 mg | N/A | N/A |
| 1 – 8 years | 2,500 mg | 2,500 mg | N/A | N/A |
| 9 – 18 years | 3,000 mg | 3,000 mg | 3,000 mg | 3,000 mg |
| 19 – 50 years | 2,500 mg | 2,500 mg | 2,500 mg | 2,500 mg |
| 51+ years | 2,000 mg | 2,000 mg | N/A | N/A |
Vitamin D & Calcium
Vitamin D is essential for calcium absorption. Known as the sunshine vitamin, it helps the body produce calcitriol, which enables calcium absorption. If you need calcium supplements, also consider taking vitamin D. Despite its availability from sunlight, more than half the world’s population is at risk of vitamin D deficiency.
Magnesium & Calcium
Magnesium is crucial for keeping calcium dissolved in the blood, preventing issues like kidney stones and arthritis. It also supports heart health, normal blood pressure, and a relaxed mood. Magnesium deficiency can hinder vitamin D absorption, which in turn affects calcium absorption. Magnesium orotate is the most bioavailable magnesium supplement.
Best Calcium Supplement Options
For optimal calcium absorption, I recommend calcium orotate. Intracal? offers a plant-based source of calcium orotate, providing 90 mg of elemental calcium and 45 mg of elemental magnesium, maintaining a 2:1 ratio. For adequate vitamin D intake, I suggest Global Healing’s Vitamin D3, a vegan, GMO-free, certified-organic liquid with 5,000 IU of lichen-derived vitamin D per serving.
