How Is Calcium Used in the Body?
Most of the calcium in your body, about 98%, is stored in your bones, with another 1% in your teeth. The remaining calcium plays a crucial role in cell-to-cell communication. Calcium ions (Ca++) are essential for brain cells to release neurotransmitters and for muscle cells to contract. This mineral is vital for your overall health.
What Is Calcium Deficiency?
Calcium deficiency, or hypocalcemia, occurs when there are insufficient levels of calcium in the blood. Calcium insufficiency, on the other hand, means you are not meeting the recommended daily intake set by health organizations like the Food and Nutrition Board (FNB) of the Institute of Medicine in the United States. Hypocalcemia is more severe than insufficiency. Groups at higher risk include the elderly, pre-teens, teenagers, vegans, overweight individuals, and those with low income.
Calcium deficiency is rarely due to a lack of dietary calcium. It is more often 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, and corticosteroids.
Calcium Deficiency Symptoms
When your body lacks calcium, it can lead to conditions like osteopenia and osteoporosis. Osteopenia refers to low bone mineral density, which can progress to osteoporosis, a condition where bones become porous and more prone to fractures. Osteoporosis is a significant cause of fractures worldwide, affecting women more frequently than men.
Hypocalcemia is particularly concerning because the body will draw calcium from the bones to maintain essential functions like brain, heart, nervous system, skin, and muscle operations. Symptoms of hypocalcemia include:
– Weak or brittle nails
– Weakened 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
Research from the National Center for Geriatrics and Gerontology indicates that calcium deficiency can deteriorate both bones and the cardiovascular system. Studies suggest that calcium deficiency may contribute to high blood pressure.
Calcium Deficiency & Brain Health
There are observed links between calcium deficiency and Alzheimer’s disease. Increasing calcium and vitamin D intake may reduce some risks associated with Alzheimer’s. Additionally, low calcium levels have been noted in adults with anxiety and headaches. Calcium is crucial for memory and cognition, and changes in calcium levels can affect brain aging. To maintain brain health, ensure adequate calcium and vitamin D intake.
Groups at Risk of Calcium Deficiency
Certain groups are more susceptible to calcium deficiency and should monitor their diet and supplement intake closely.
Post-Menopausal Women & Older Adults
During menopause, reduced estrogen levels decrease calcium absorption into bones, leading to significant bone mass loss. Post-menopausal women can lose 3-5% of their bone mass per year initially, slowing to 1% annually thereafter. Consuming high-calcium foods and taking calcium and vitamin D supplements can help. Older adults should also monitor their calcium intake to avoid exceeding recommended limits, which can have its own risks.
Amenorrheic Women (without menstruation)
Women who lose too much body fat may stop menstruating, which decreases calcium absorption and increases calcium excretion. This is common in athletes or those with eating disorders like anorexia nervosa. These women are at higher risk of stress fractures.
Vegans & Vegetarians
Vegans, who do not consume any animal products, are at higher risk of calcium deficiency due to the lack of dairy in their diet. Vegetarians, who may consume dairy, still have a slightly higher risk compared to those who eat both meat and dairy.
Low-Income Households
Data shows that low-income individuals in the United States are at higher risk of calcium insufficiency. Surveys from 2001 to 2010 indicate that calcium intake increases with income.
Teenagers
Teenagers, especially 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 adequate calcium intake through diet or supplements.
Overweight Individuals
Overweight and obese individuals are also at higher risk of calcium insufficiency. Studies suggest a link between calcium intake and lower body weight, although calcium supplementation alone does not cause weight loss.
People With Digestive Conditions
Conditions like celiac disease and inflammatory bowel disease (IBD) can impair calcium absorption, leading to deficiencies. Supplementation is often recommended for adults with these conditions.
How to Counteract Calcium Deficiency
To reduce the risk of calcium deficiency, maintain a healthy lifestyle that includes a balanced diet, regular exercise, and stress management. A plant-based diet rich in organic fruits, vegetables, nuts, and seeds is beneficial. If you consume dairy, choose organic, pasture-raised options. Regular exercise and avoiding obesity are also important.
If you are at higher risk of hypocalcemia, monitor your calcium intake and have your blood calcium levels tested periodically. Increase your consumption of calcium-rich foods and take supplements if necessary. If diagnosed with hypocalcemia, your healthcare provider may prescribe hormone supplements, medications to increase calcium absorption, and vitamin D and calcium supplements.
Recommended Calcium Intake
The Food and Nutrition Board at the Institute of Medicine recommends the following daily allowances for calcium:
| 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
While dairy products are well-known sources of calcium, many vegetables are also rich in this mineral. Here are some calcium-rich foods:
| 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 calcium or if you are at higher risk of deficiency, consider taking a calcium supplement. Consult your healthcare provider to determine the appropriate amount.
Types of Supplements
Calcium supplements come in various forms, including calcium orotate, calcium carbonate, and calcium citrate. Calcium orotate has the highest bioavailability, while calcium carbonate has the lowest and must be taken with food. Calcium citrate is better absorbed than calcium carbonate.