Do Women in Menopause Need Calcium? The Great Calcium Debate - Part 1

What's the confusion when it comes to calcium? Isn't calcium one of the key ingredients in keeping our bones healthy?

When I first started studying nutrition, Mariah Carey's song 'Fantasy' topped the charts for weeks. A lot has changed since 1995, including what we know about nutrition and bone health, which is what inspired this reel about calcium.

One of the biggest changes has been around the advice we give women in midlife about the benefits (and risks) regarding calcium supplements. When I qualified as an RD in 2000 (eek!), it was a no-brainer to tell women to eat 2-3 servings of calcium-rich foods per day, and that taking a supplement was often necessary to ensure we hit the 1200 mg target. It was also generally accepted that a little more than that wouldn't hurt and may actually be beneficial. This was even more true for women over 40.

All of this advice was given with one goal in mind - to prevent osteoporosis and fractures. And fractures are no joke, with an estimated 1 in 3 women and 1 in 5 men suffering an osteoporotic fracture during their lifetime. (FYI: these are Canadian stats)

And since it was (and still is) well known that calcium was critical for building healthy bone, it was assumed that it also helped to maintain healthy bone, thereby reducing the risk of fractures. But it wasn't until the mid-2000s that research took a closer look at whether calcium supplements actually prevented fractures. And guess what? It turns out that they don't, as this 2017 review highlighted.

But what about calcium-rich foods? Are they good for bone health?

In pre-menopausal women (especially under 25)? Yes! In post-menopausal women? Maybe. Maybe not. We actually reach peak bone mass by 25 years of age, 30 at the latest, so calcium intake before that is critically important. Everything after that is about maintaining bone and slowing the rate of loss. As this study found, "postmenopausal bone loss is unrelated to dietary calcium intake. This suggests that strategies to increase calcium intake are unlikely to impact the prevalence of and morbidity from postmenopausal osteoporosis.

So you're saying we can stop trying to get enough calcium?

No, because calcium is the most abundant mineral in the human body, and it's kinda important for a whole bunch of other reasons!

Muscles rely on it to contract and relax, including your heart.
Nerve cells use it to communicate.
It's involved in activating the blood clotting process.

So your body still needs it, even if your bones don't. But the good news is that you can probably aim for something closer to 800 mg instead of 1200 mg, which is what the recommendation used to be prior to the late 1990s, which was the start of the "if some is good, more may be better" mindset regarding vitamins and minerals.

Is milk really the best source of calcium?

Before I answer that question and dive into other food sources of calcium, let's pause for a quick discussion about bioavailability which is the amount that is actually absorbed and used by your body. Not all foods have the same bioavailability. For example:

1 cup of milk has 300 mg of calcium, but only about 100 mg is absorbed because dairy products have an average bioavailability of 30%.
Leafy greens boast a 50% bioavailability, but this is reduced by other naturally-occurring plant compounds (phytates and oxalates), may require cooking to release the calcium, and much larger volumes are required. Using raw kale as an example, 4 cups would be needed to provide 100 mg of bioavailable calcium. (reference: USDA)

Just tell me what to eat already!

It probably will surprise no one that my advice will always be to prioritize satisfaction over nutritionism. Meaning, don't rely solely on the calcium content to decide what you should eat. But here's a little framework for choosing calcium-rich foods intuitively and with intention.

If you enjoy and tolerate dairy foods, then feel free to include these!

If milk isn't your thing (it's not mine either), yogurt and cheese are also good sources of calcium.
Hard and older cheeses have more calcium than fresh cheese and are also a source of Vitamin K2, which I'll dive into next week in part 2 of this discussion around bone health.
FYI, Greek and Icelandic yogurts come in slightly lower than regular yogurt on calcium content, but I'd still recommend letting your taste buds be the guide on this one.

If you're looking for non-dairy sources, there are lots of choices!

Non-dairy milks are an easy choice. I use fortified soy milk in my smoothies, but almost all non-dairy milks are fortified with calcium, so there's no top contender here.
Trying to get more plants on your plate? Great! Low-oxalate greens including kale, broccoli, and bok choy will provide more bioavailable calcium than swiss chard and spinach. And enjoying them cooked instead of raw will help to reduce the oxalate content and increase the amount of calcium you can absorb.
Tofu is another great non-dairy source, providing close to 350 mg of calcium in 100 gm (1/3 cup), as is 1 cup of edamame (100 mg of calcium).
Sardines (yes, sardines) provide 350 mg per can, and canned salmon will give you 200 mg of calcium in about 1/3 of a can. Why canned? Because of the bones!

Pro tip: Are you making mental notes of which foods are "best"? Watch for that sneaky all-or-nothing thinking mindset. I'm not saying you should never eat a spinach salad, or always choose broccoli. Choose what you enjoy, that is accessible to you, and use this information to help guide your choices. Remember, diversity is the name of the game when it comes to nutrition.

Is there ever a time and place for calcium supplements? Yes, and far too many reasons to list here. In general, this information applies to healthy women who do not have existing medical conditions that would increase the need for calcium. But as always, this isn't medical advice, just information. So always talk to your health care team about what's right for you.

Here's the TLDR (aka Coles notes): Calcium supplements have not been shown to reduce the risk of fractures in healthy postmenopausal women. But calcium is still important for other reasons, so include a range of calcium-rich foods that you enjoy. But you don't have to drink milk or eat kale.

Whew! We've reached the end of Part 1. Stay tuned for next week for Part 2: If not calcium, then what? where I'll touch on the other things we can do to keep our bones healthy in midlife including a discussion around vitamins D and K2.

Need help making peace with food in midlife?