Menopause is the time in a woman's life marked by a decline in her menstrual cycle. It is designated by one full year without menstruation and characterizes the natural decline of her ovarian egg reserve, and thus her ovarian production of the female hormones, estrogen and progesterone. These hormones provide female sex characteristics, such as breasts, hips and female hair distribution. Estrogen and progesterone also play an intricate role in calcium metabolism and bone health.
The Role of Calcium
Calcium is a very important mineral component to the tissues of the body and has very diverse functions. It is also the most highly concentrated mineral in the body, maintained predominantly in the bone with only a small percentage available, albeit under tight control, in the bloodstream. The National Institutes of Health (NIH), Office of Dietary Supplements notes that the less-than-1-percent circulating calcium available is active in the processes allowing for contraction and dilation of the arteries, function of the muscles, nervous signal transmission, communication between cells and hormone release. The remaining 99 percent that is bound up in the bones and teeth provides the strength, stability and hard structure of the human skeleton.
Calcium and Hormones
Bone is an active tissue, contrary to its stagnant and stationary appearance. The process of bone growth, which allows for increases in height and growth of the skull and long appendages, occurs as a flux of bone resorption and calcium-dependent bone deposition. In young people, this process results in a positive gain, as the amount of bone and calcium deposited is greater than the bone broken down. This positive gain is a result of circulating hormones, like estrogen, which in pubescent years of life are also in their prime potency.
The NIH, Office of Dietary Supplements notes that in middle adulthood, the bone-breakdown and bone-building phases are about equivalent, but as older age sets in, and in particular as a woman enters menopause, the decline in estrogen and other hormones negatively impacts bone and calcium deposition. The seesaw is now in the opposite direction, with bone resorption exceeding bone growth. In an attempt to compensate, calcium and other bone-building nutrient intake expectations increase.
Calcium Requirements after Menopause
The average age of menopause onset is 50 years. The Linus Pauling Institute at Oregon State University notes that in the postmenopausal years, covering ages 51 through 70 years, the recommended dietary allowance, or RDA, of calcium for women goes up from 1,000mg per day to 1,200mg per day. Prevention of osteoporosis is the biggest concern surrounding sufficient calcium intake. Osteoporosis occurs when the bones become less dense and more porous. The Institute further notes that the prevention of osteoporosis is also dependent on attaining proper vitamin D levels. Vitamin D enables optimal calcium absorption.
Calcium Sources
Calcium can be attained from a variety of food sources. Dairy products are the most well-known source of calcium. The Centers for Disease Control and Prevention notes that low-fat or nonfat milk, cheeses and yogurt are calcium rich. However, for people with medical issues such as food allergies and lactose intolerance that render them unable to ingest dairy, the CDC recommends dark green leafy vegetables, such as bok choy and broccoli, nuts including almonds, and calcium-fortified foods, like cereals, orange juice and soy.
