Pregnancy, Breastfeeding, Menopause: The 3 Times You're Losing Bone | Dr. Vonda Wright

**Vonda Wright** (0:00)
Hi, and welcome to the Unbreakable Bone mini-series. I'm Dr. Vonda Wright, your orthopedic sports surgeon, longevity, and women's health expert. Today, we're going to be talking about bone and how it's built and how we build it on a timeline. We build bone on a timeline, and we also lose it on a schedule. And what do I mean by that? Well, let's talk about it. Timing determines your skeletal destiny. How quickly we step in front of the time bombs that are gonna take our bone from us. So let's talk through the timeline of bone. Sometimes we think that osteoporosis is a disease of old people. And I can tend to you that osteoporosis and the fractures that happen as a result of it do tend to happen in older people. But bone health and loss of bone health is a disease of young people. Let me tell you what I mean. Let's talk about the life history of bone. When we're born, we don't have hard bones. We have a skeleton made of cartilage, which is the soft tissue that we find in adulthood at the end of our bones. But when we're born, we're all cartilage. And over time, and especially around the time of puberty, our bones harden. Such that between about 15 and 25, we will grow bone, we will harden our bone, and reach a peak bone density and mass around 25 in women and 30 in men. And that is due to all the things we talked about in the last episode. How much we eat, how much activity we have, what are our genetics, are we active, what are our hormones doing? All of those play key components to the building of bone. So that we reach again our peak bone, about 25 to 30, that is really early. And then what happens? Well, as I said, we level out, and then in our 30s, we begin to lose bone, both men and women at about 1% per year. It's normal, it's what our bodies are meant to do. But then for women, we reach another phase in our life, one unexpected and one we are talking about all over the place now. The bone we accrue in our youth, and we want to reach the peakiest peak, the highest peak, because it cannot be fully replaced by all the interventions that we've talked about later in life. We want to reach the highest peak, because what happens? During our fertility years, those years when women decide to have children, if they decide to have children, there are two opportunities to weaken our bones. Now, before I tell you about them, the good news is we are fully equipped to replace the bones we lose during pregnancy and breastfeeding, but only if we are eating and replacing what we've used. So let's unpack this. During pregnancy, it is estimated that you require 500 milligrams of calcium a day to build a baby. When you are building a baby, your body is going to prioritize that job. Prioritize the skeleton of this baby and the building of this baby. If we are not eating adequately or genetically predisposed, we can develop something called the osteoporosis of pregnancy. We can lose, depending on what data you read, between 6 and 20 percent of our bone density during this time. So the osteoporosis of pregnancy manifests as spine fractures and long bone fractures. During a time when you have no time to be healing or to be in pain, many people do not know that this exists. And so it's not prevented, and sometimes we don't know about it until you break. Osteoporosis of pregnancy. And then what happens? You give birth to the baby. And for those women who choose to breastfeed, come let me just stop here and say, again, you are a sentient being, you have agency, you get to choose, and I am in full support of breastfeeding. In fact, with my 18-year-old daughter, I breastfed her for a whole year and would have probably gone on and on, except she was done with that business. A surprising fact that is little known is that during breastfeeding, babies also require about 500 milligrams of calcium a day to make the milk that they need. Well, where is the woman going to get that calcium? She can get it from whole food, which is the preferred source. But if we're too busy or too tired or we just lose track and are not eating enough calcium, your body will take the calcium you need to make breast milk from your bones. Now, if we know that, we can get in front of it. But if we don't, then that is another time in the life cycle of a woman's life when she can endanger her bones. Or that you can lose so much calcium from our bones during breastfeeding. And remember, the good news is your body knows this is going on in this period of life and can fully replace you, but only if you're eating enough. Very important. But then what happens? So we get through this fertility period in our life, and then we enter perimenopause. We've already talked about perimenopause a little bit, where it is the normal, natural life cycle of human and animal ovaries to run out of eggs. Just as a brief review, we are born with all the eggs we're ever gonna have. So isn't it a miracle that this little girl you're holding, your daughter, your niece, your friend's kid, in her little ovaries, she has two million eggs, and that's all she's gonna have. So the whole future of your family is in this little baby's ovaries. And then as she grows and matures, she'll lose eggs every month. Until at age 40, she has about 1% left. Where is estrogen made? Estrogen is made mostly in the follicle or the shell of the egg. When we have too few eggs, we're not gonna be able to make enough estrogen. What happens when we don't have enough estrogen? Well, we talked about in prior parts of this series that estrogen is critical for the balanced breakdown and building of bone. It's not that we have given up building bone during perimenopause and menopause. It's just that the breakdown is much faster than the building due to the loss of estrogen. So during the perimenopausal phase of life, which is around the mid-40s, it can last for five to seven years. Our rate of bone loss increases three, five. Some papers say up to 7% a year during perimenopause and early menopause, which that you can lose 20%.