Calcium and Healthy Bones
5-Minute DIY Milk:
1 cup overnight-soaked almonds
4 cups water
2 dates or a handful of strawberries
Blend in a high-speed blender, then strain through a nut milk bag (also good for making cold brew coffee!). Keeps for 3 days.
Got Milk?
When many of us think of healthy bones, we often think of milk, because… we need calcium for strong bones, right? After all, according to the famous slogan, “Milk, it does a body good!” But this messaging didn’t come from the government or science… it came from Big Ag. It’s a clever way for the dairy industry to get you to buy more of their subsidized product. And we’ve seen the message—on billboards, in grocery stores, in doctor’s offices—so frequently that we’ve taken marketing for truth. But by overindulging in milk, we are subjecting ourselves to harmful hormones, antibiotics, and sugar/lactose (all causative factors for obesity, Type-2 diabetes, osteoporosis, and cancer), while subjecting unthinkable cruelty on mama and baby cows and the humans who work in, or live near, the industry facilities. In our best efforts to cover our nutritional bases, we’re consuming a lot of dairy and often take unnecessary calcium supplements (again, good marketing), which can lead to health problems while not actually doing much for building bone.
What is Calcium?
Calcium is a mineral utilized by the body, mainly for healthy bones and teeth, and it comes from the earth. Calcium is not made by mama cows! Calcium is in the soil and passes from the ground into the roots of grasses and plants. Cows get their calcium from eating grass, which is then passed on to humans in their milk product. It might surprise you to learn that the bioavailability (ability of a substance to be absorbed and utilized by the body) of milk is lower than that of vegetables, where you get calcium directly from the source!
99% of the body’s calcium supply can be found in teeth and bones, but it also serves a role in allowing blood to clot and muscles to contract. There are two ways the body gets the calcium it needs:
1. From the food and supplements you feed it, and
2. By “borrowing” it from your bones if you don’t provide enough through your diet.
Click here for a quick look at this amazing body and all the organs and systems that work in synergy to create homeostasis needed for healthy bones.
On Dairy
Since most people associate calcium with milk, let’s start with dairy. While dairy is indeed a source of calcium, it does come with some baggage. For starters, since many people are lactose intolerant, dairy can create all kinds of issues in the body, ranging from bloating, cramps, gas, and headaches to acne, eczema, and allergies. Tip: If this describes you, try taking dairy, in all its myriad forms, out of your diet—entirely—for three weeks and see what happens.
Another issue with dairy is the correlation we’re seeing with certain cancers, like breast cancer in women and prostate cancer in men. One reason for this is insulin-like growth factor (IGF-1), which is produced by the body when you drink milk. As a kid, it’s responsible for your growth, but, as an adult, circulating IGF-1 in the system is positively associated with breast and prostate cancers. You can read some of the research here and here.
In 2022, researchers conducted the first large-scale study to investigate dairy consumption and cancer risk in Chinese adults. Dairy consumption in China has always been much lower than consumption in the US, but has risen rapidly in recent years, likely due to Western influence. This study followed 510,000 participants over the course of 11 years and concluded that there may be a direct link between regular dairy consumption and certain cancers, notably breast cancer.
A 2023 study called out the definitive association between milk consumption and the risk of estrogen receptor-a-positive breast cancer carcinogenesis (along with other issues) and concluded the report with a strong suggestion: we must reconsider the recommended dietary guidelines on milk consumption.
There are other issues connected with dairy consumption. Weight gain is one (surprising, since the billboards tell you it helps with weight loss!), since it’s anabolic in nature. It literally exists to feed a baby cow so it can grow quickly into a 1,200 lb. vegetarian creature! Another issue is that dairy doesn’t just come with excess weight or other human health concerns. It is also an animal welfare, environmental, and feminist issue (stay tuned for that discussion!). Just this week, nearly 20,000 dairy cows died after a Dimmitt, Texas facility exploded (luckily, only one worker was injured). Twenty thousand dairy cows waiting to be milked by machines. Their screams captured on video will haunt me forever. The dairy industry is massive, and this loss is catastrophic. Tragedies at dairy facilities are not unusual, though this particular incident is the largest mass death of cattle in U.S. history.
On Calcium and Vitamin D Supplements
In their efforts to do the “healthy” thing, so many people jump on the supplement wagon without evaluating their current calcium and vitamin D needs. While supplementation is appropriate for some, it is not necessary for everyone (or most)—especially if it surpasses the recommended daily allowance. But what’s the harm in having high levels of calcium in the body or taking supplements as a preventative? Isn’t more better? Shouldn’t I just take a supplement to cover my bases? The research is clear: NO. There is no benefit to ingesting calcium in amounts that exceed the recommended daily allowance. In fact, if calcium levels are elevated by diet or supplements (high levels caused by parathyroid tumors, etc. are a different issue), then it can create kidney stones and risks for those on dialysis. It can also lead to nausea, gut pain, and other GI issues. For men, there are links to prostate cancer (watch your whey protein intake, men!). Furthermore, there have been recent studies linking calcium supplements to increased risk of cardiovascular heart disease in otherwise healthy postmenopausal women.
The $30 billion-a-year supplements industry creates marketing that makes us believe we will successfully preserve bone and prevent osteoporosis and fractures by taking their pills, but it isn’t necessarily true. For one, the supplements industry isn’t regulated like pharmaceuticals, so anything goes. In 2015, the New York Attorney General tested the ingredients of a selection of herbal supplements sold at Walmart, Target and other major retailers. They found that the supplements did not contain the ingredients listed on the label. In fact, 80% of the products tested did not contain the key ingredients listed! When you take supplements, it can be a crapshoot. If you’re seeing a medical practitioner selling their own supplements, you should be seeing red flags and looking for a second opinion.
In addition to ingredient and labeling issues, the research is ongoing and often fraught with disagreement. That said, some studies show: excess calcium can increase the risk of cardiovascular disease in older adults while not necessarily doing much to prevent bone loss. A 2021 study found a 15% increase in cardiovascular disease by postmenopausal women taking calcium supplements. Another study shows that the risk of cardiovascular disease outweighs the benefit, in terms of preventing fractures in older adults, especially postmenopausal women, where it comes to taking calcium and vitamin D supplements. The US Preventive Services Task Force, after years of research, still claims the findings are inconclusive, where it comes to the benefits of supplementing with calcium and vitamin D to prevent fractures in postmenopausal women. However, it has concluded that supplementing with calcium and vitamin D increases the instance of kidney stones.
Numerous studies have been conducted to test the human body’s need for calcium, and “(w)hile inconclusive, the current evidence for calcium supplementation is concerning for increased [cardiovascular disease] risk. In this light, we suggest that the recommended daily allowances of calcium be achieved through dietary sources when possible, and that the smallest effective supplemental doses be considered in populations at risk of osteoporosis only after dietary modifications have been exhausted.”
Since calcium and vitamin D are so intimately connected, they are often taken together in one supplement. New research is looking at this stacking, and, while not conclusive, results are showing a possible connection between the combo and risk of stroke. Another study also cautions the combo, but again, the results aren’t conclusive, as others have noted.
More research is needed, as there isn’t a consensus across the board (and with industry-backed studies, be it dairy, supplements, or other health interests, there likely will never be!). But there does seem to be some agreement that individuals should address their calcium and vitamin D needs through diet first, and only then reach for the supplements. We can provide ourselves the best in preventative medicine by:
1. Meeting the recommended calcium and vitamin D2 daily allowance by addressing our food choices and intake;
2. Depending on location, weather, and skin type, get a modest amount of sunshine (i.e., 15-20 minutes most days) in order to produce our own D3;
3. Exercising regularly to place healthy stress on the bones so that they regenerate. Some researchers note it’s better to be physically active than drink milk, if the goal is stronger bones.
A pill won’t make up for a deficient lifestyle.
If you need pills/supplements, it could be an indication that your diet needs some work.
Plant-Based Calcium Sources
As I stated above, the body’s ability to absorb calcium from vegetables is higher than its ability to absorb calcium from milk. Some good plant sources of calcium:
Beans
Broccoli
Brussels sprouts
Green beans
Kale, collards, and other leafy greens (note: while spinach is a good source of calcium, its absorption rate is quite low.)
Tofu
Blackstrap molasses
Figs and prunes
Sesame seeds/tahini (I like chewing 1-2 Tbsp. first thing in the morning)
Fortified foods (non-dairy milks, orange juice, cereals, etc.)
Fun fact: According to the USDA, one serving of chocolate almond milk has 100 mg. more calcium than one serving of 2% or skim dairy milk. One serving of tofu has a whopping 500 mg. more calcium that a serving of dairy milk, nearly satisfying the recommended daily allowance (RDA) for calcium!
Vitamin D Sources
Vitamin D, or calciferol, is important, as it aids in the absorption of calcium in the body. We need vitamin D to make the most of the calcium we ingest. The best way to supply yourself with vitamin D is through sun exposure, but that can be difficult for some. The further away from the equator, the more difficult it can be to get adequate sun. Sunscreens and cloudy skies can also block the sunrays we need. You don’t need a lot of sun, and not full sun during the hottest part of the day, but 15-20 minutes of exposure on your arms and face several days a week is sufficient to meet your vitamin D needs. If you live in a cloudy, rainy environment or have dealt with skin cancer, consult your doctor about taking a supplement. It might make sense in your situation.
10-15 minutes of sun exposure
Vitamin D can also be found in mushrooms and fortified foods (e.g., non-dairy milks, juices, cereals).
How much calcium and vitamin D do we actually need?
According to the NIH (and Institute of Medicine, IOM, now known as the National Academy of Medicine, NAM):
Calcium: women under 50 need 1,000 mg/day and women over 51 need 1,200 mg/day. Since men aren’t dealing with dropping levels of estrogen, their values are slightly different. Men under 70 need 1,000 mg/day and men over 71 need 1,200 mg/day.
Vitamin D: for both women and men under 50: 400-800 mg/day and over 50: 800-1,000 mg/day
The upper limits for calcium intake are 2,500 mg/day for adults under 50 and 2,000 mg/day for adults over 51.
A nod to vitamin K2
Vitamin K2 (at least 32 mcg) has been found to offset the cardiovascular disease risks associated with supplemented calcium by inhibiting arterial calcification and stiffening. Good sources of K2 are green leafy vegetables, spinach, broccoli, tempeh, and fortified foods. It doesn’t take much, either. Just one cup of leafy greens or spinach will cover your daily needs. The IOM recommends 90 mcg/day for adult women and 90 mcg/day for adult men.
Other preventative factors you have control over:
Exercise: weight bearing (walking, jogging, dancing, strength training) movements place healthy stress on the bones
Stop smoking
Maintain a healthy weight
Avoid alcohol
Conclusion
With years of scientific studies and researchers continuing to report the overall findings “inconclusive,” we must take more responsibility for our health outcomes by addressing our needs through diet and lifestyle. There is no magic pill, but there are actions you can take to improve your longevity. You can get adequate calcium and vitamin D to support bone health and prevent osteoporosis and fractures by addressing these needs through your diet. The bonus to focusing on food sources is you’ll be ingesting more fiber, protein, and vitamins from the healthier foods. Supplementation should come as a last resort for those unable to meet the minimum requirements through diet or have particular needs after a medical diagnosis.
Healthy bones are also a result of an active lifestyle: getting a little sunshine and weight-bearing exercise everyday is a great preventative—for osteoporosis and many other diseases. The bonus of getting outside and moving is elevating the mood while helping you maintain a healthy weight. A healthy weight is key to preventing cancer, osteoporosis, joint problems, diabetes, vasomotor symptoms during the menopausal transition, and more. And, as it’s recommended across the board, stop smoking and eliminate alcohol from your life for better health.
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