Calcium is the most abundant mineral in the body, and almost 99 percent of the body’s calcium is stored in the structure of the bones and teeth. The truth is, though, many of us aren’t eating enough foods high in calcium. Wikipedia calls calcium supplementation “controversial” but admits that since 2010, the FDA has permitted the health claim that calcium and vitamin D supplements together protect against osteoporosis. Qualified health claims regarding the mineral’s effectiveness in reducing the risks of colon cancer and hypertension are also permitted. New England Journal of Medicinefinds calcium supplementation reduces the risk of recurrent colorectal adenomas. Calcium also plays a central role in blood cell synthesis, protects against stroke, especially in conjunction with magnesium and potassium, contributes to bone growth and development, and lowers blood cholesterol.
A PubMed search yields 563,919 results for calcium and the nutrient is ubiquitous in bodily processes. European Journal of Nutrition confirms calcium’s effectiveness in improving bone mineral density in teenage girls. Public Health Nutrition adds that in addition to its preventive benefits against the disease, calcium reduces the rate of bone loss in patients who already have osteoporosis.
What Is Calcium? Role of Calcium in the Body
Calcium is an essential chemical element found within the human body that typically appears as a soft silver-gray metal. Not only is calcium stored in the bones and teeth of humans and many other animals, but it’s found inside certain layers of the Earth’s crust. (1)
What is the role of calcium in the body? Bone calcium is used as a storage area to release calcium into the bloodstream when it is needed. Calcium is needed for so much more than bone health, though. Eating calcium-rich foods makes it possible for our bodies to achieve optimal nerve transmission (or “intercellular nerve communication”), blood clotting, hormone secretion and muscle contraction. (2) Another surprising benefit of eating calcium-rich foods? They may help to control your appetite and potentially facilitate weight loss. It’s believed that calcium foods can enhance sensations of satisfaction after eating, especially when someone is following a low-fat diet or restricting calorie (energy) intake. (3)
Blood calcium is tightly controlled since it plays so many critical functions, including balancing your body’s acid/alkaline body and pH. The body borrows calcium from the bones as needed. In fact, this happens so often that the bones are actually rebuilt about every 10 years. Calcium is also important for controlling levels of magnesium, phosphorus and potassium in the blood.
How many grams of calcium do you need per day to meet your calcium needs? According to the National Institutes of Health, here are the recommended daily value for calcium: (4a)
- Birth to 6 months, 200 mg
- Infants 7–12 months, 260 mg
- Children 1–3 years, 700 mg
- Children 4–8 years, 1,000 mg
- Children 9–13 years, 1,300 mg
- Teens 14–18 years, 1,300 mg
- Adults 19–50 years, 1,000 mg
- Adult men 51–70 years, 1,000 mg
- Adult women 51–70 years, 1,200 mg
- Adults 71 years and older, 1,200 mg
- Pregnant and breastfeeding teens, 1,300 mg
- Pregnant and breastfeeding adults, 1,000 mg
Is Dairy Really the Best Source of Calcium?
Many studies have investigated whether or not dairy, and cow’s milk in particular, is the ideal source of calcium. Results have been mixed, with some observational studies showing that dairy has a positive effect on bone health, while others show that it has no effect, or even potentially harmful effects in certain cases.
One of the reasons that dairy products are often promoted as being the best source of calcium is because not only do dairy products contain calcium, but full-fat, grass-fed dairy foods are also a good source of vitamin K, phosphorus, and to some degree Vitamin D too. These nutrients are all equally important in supporting bone health as calcium is, because they work together to maintain bone mineral density. (18)
Another positive aspect of getting calcium from high quality dairy products is that dairy foods are high in protein. Although the opposite was initially thought to be true, recently many studies have found a significant positive relationship between higher protein intake and increased bone mass or density. According to researchers who conducted a 2011 study to investigate the effects of protein on skeletal health,
“The recommendation to intentionally restrict dietary protein to improve bone health is unwarranted, and potentially even dangerous to those individuals who consume inadequate protein.” (19)
Recent research shows that a diet high in calcium and also high in protein and other essential nutrients can positively impact bone health by aiding in more calcium absorption due to several biological mechanisms. Therefore for optimal bone health, it’s advised to eat high levels of calcium along with other important cofounding minerals and substantial protein too. Most of these nutrients can be found in high-quality dairy products like organic whey protein, raw unpasteurized milk, organic goat cheese, and kefir. (20)
One source of calcium that is almost ideal is raw milk. Raw milk is different from the normal cow’s milk, or even organic cow’s milk, that you’d find in the grocery store because it is just that- it’s fresh, raw, unpasteurized, and non-homogonized. This is what distinguishes raw milk from regular milk; it’s the processes that it doesn’t go through that retains its nutrients.
Raw also milk comes from healthy cows that are grass-fed and obtain more nutrients than conventional dairy cows, therefore their milk is higher in nutrients too. Only a small population of people choose to take advantage of raw milk’s benefits, while many more consume pasteurized dairy that is lower in nutrients and may actually harm bone health. This is the case because dairy milk becomes acidic when it goes through pasteurization and homogenization processes, and acidic substances actually harm bone health by forcing the body to leach alkaline substances from the bones in order to balance the pH level of the blood. Raw milk on the other hand, in its all natural state, is an alkaline food that supports bone health.
That being said, it’s also possible to get enough calcium without consuming dairy products. Vegetarians and vegans who eat a well-rounded whole foods diet for example can acquire calcium from plant sources including sea vegetables, beans, and leafy greens.
Top 10 Foods High in Calcium
Most people immediately think of dairy products when they hear calcium, especially milk. While milk and other dairy products are certainly good sources of calcium, they aren’t the only options. It might surprise you that many different types of nondairy plant and animal-derived foods — including vegetables, fish, nuts and beans — also provide calcium. (4b)
Below are the top 10 foods high in calcium based on calcium content:
- Sardines (canned with bones included) — 1 cup: 569 milligrams (57 percent DV)
- Yogurt or Kefir — 1 cup: 488 milligrams (49 percent DV)
- Raw Milk plus (whey protein, made from milk) — 1 cup: 300 milligrams (30 percent DV)
- Cheese — 1 ounce: 202 milligrams (20 percent DV)
- Kale (raw) — 1 cup: 90.5 milligrams (9 percent DV)
- Okra (raw) — 1 cup: 81 milligrams (8 percent DV)
- Bok Choy — 1 cup: 74 milligrams (7 percent DV)
- Almonds — 1 ounce: 73.9 milligrams (7 percent DV)
- Broccoli (raw) — 1 cup: 42.8 milligrams (4 percent DV)
- Watercress — 1 cup: 41 milligrams (4 percent DV)
Benefits of Foods High in Calcium
1. Supports Bone Health
Calcium is involved in the growth and maintenance of bones. Calcium, together with other essential minerals like Vitamin K and Vitamin D, is needed to maintain bone mineral density and to prevent weak, brittle bones and fractures. It helps form a part of hydroxyapatite, the mineral complex that makes your bones and teeth hard and maintains bone density and helps bones heal.
Without enough calcium present in the body, bones are susceptible to becoming post and pliable, and therefore they’d be more prone to fractures and breaks.
For bone loss prevention, vitamin D, vitamin K, and protein are just as important as calcium is, therefore the three of these factors together can result in the best chances of protecting bones into old age. (21, 22)
That being said, consuming high levels of calcium alone, or taking calcium supplements, does not protect against bone problems like osteoporosis and fractures. In fact it may even slightly increase the risk for bone fractures. Calcium needs to be obtained from natural food sources to have the most benefits and because of this, the use of calcium supplements for preventing bone related diseases is now being rethought.
2. May Help Prevent Osteoporosis
Calcium aids in bone strength as the bones build up calcium stores over time. Calcium supplementation has been one of the standard treatment methods used to prevent and decreases cases of osteoporosis for decades.
Osteoporosis is a disease most common in women (especially postmenopausal women) that results in weak, fragile bones over time due to bone deterioration and loss of bone mineral and mass; what really occurs when someone has osteoporosis is that their bones become porous (hence the name).
Although recently there are many studies pointing to the fact that calcium alone may not directly positively influence osteoporosis risk, eating foods with plenty of calcium along with protein, vitamin K, and vitamin D can help reduce your risk for bone related problems.
3. Helps Lower High Blood Pressure
Calcium is involved in regulating heart functions because of its role in dilating blood vessels and sending chemical nerve signals from the brain to the heart. This is important for regulating heart rhythms, blood pressure, and circulation.
Supplemental dietary calcium has been shown to help lower levels of high blood pressure, whereas restricted calcium diets tend to elevate blood pressure. (24) In studies, patients have experienced a statistically significant decrease of systolic high blood pressure with calcium supplementation. (25)
It’s believed that calcium may alter blood pressure by changing the metabolism of other electrolytes and by playing a part in blood vessel activity and muscle strength. (26) However, some studies show that the effect is too small to support the use of calcium supplementation for preventing or treating hypertension at this time.
4. Defends Against Cancer
According to studies, there is a highly significant association between calcium and vitamin D intake and a lowered risk of death from at least fifteen types of cancers. (27) Of these, colon, rectal, breast, gastric, endometrial, renal and ovarian cancer studies all exhibit a significant inverse relationship between cancer incidence and oral intake of calcium.
Experimental studies have shown that calcium has anticarcinogenic effects due to its participation in regulating cell proliferation, cell differentiation, and inducing cell death (apoptosis) in cancerous cells. (28)
However it’s important to note that high calcium supplementation is not currently used as a preventive measure for cancer. More evidence is still needed and some studies even show that a high intake of calcium from certain sources, like dairy products, may actually increase prostate cancer risk.
5. Supports Muscle and Nerve Function
Calcium is involved in the release of neurotransmitters in the brain that control muscle movement and nerve signaling. Calcium helps cells communicate in order to relay nerve responses and activates certain proteins in the body which are needed by muscles to move and contract. (29) Calcium also helps with the control and release of glucose (sugar) in the blood stream, which is used by the muscles for “fuel”.
6. Helps with Weight Loss
Increasing dietary calcium may positively affect weight and fat loss. In studies, participants experienced an increase in the percentage of fat lost from the trunk (torso) region of the body when they consumed more calcium. (30)
7. Can Help Prevent Diabetes
Vitamin D and calcium consumed together may be beneficial in optimizing glucose metabolism and helping to prevent diabetes according to studies. (31) Vitamin D and calcium may have direct effects on the pancreatic cells that control insulin secretion and therefore blood sugar levels. Calcium is an essential component of cellular processes that occur within insulin responsive tissues like skeletal muscle and fat tissue.
In the famous 20-year long Nurses’ Health Study, researchers followed 83,779 women who had no history of diabetes and vitamin D and calcium intake from diet and supplements was assessed every 2-4 years. During 20 years of follow-up, the study observed that a combined daily intake of more than1,200 mg calcium and more than 800 IU vitamin D was associated with a 33% lower risk of type 2 diabetes. (32)
8. Needed to Maintain Dental Health
Calcium is stored partially in the teeth and is needed for tooth health and maintenance. Calcium may help defend against tooth decay and has been correlated with increased dental health for similar reasons that it protects bones. (33)
9. Helps with Indigestion
Calcium is used in over-the-counter antacid tablets that help digestion by reducing heartburn and symptoms of an upset stomach. (34) But antacids often just reduce your stomach acid which is the opposite of what you need. In fact, in nearly 80% of acid reflux cases, low stomach acid is the case. The reflux is actually cause by food that has been sitting in the stomach without enough stomach acid, so it ferments creating gas and pressure that reopens the LEM muscle that is the valve between your esophagus and the stomach. This allows acid to travel up and causes the burning or pressure in your chest.
Eating calcium rich foods can help reduce these symptoms because calcium helps the LEM valve that controls food moving into the stomach and when malfunctioning causes acid reflux. Taking calcium improves the LEM muscle function and can often help reverse the symptoms associated with GERD or acid reflux.
10. Can Help Prevent PMS Symptoms
Calcium has been shown to be useful in relieving PMS symptoms including bloating, cramps, headaches, breast tenderness, muscle aches, fatigue, and moodiness. (35) Calcium levels fluctuate during the menstrual cycle because as estrogen levels increase, calcium concentrations drop, therefore consuming enough calcium helps to balance this relationship and reduce painful symptoms.
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