08/24/2026
VITAMIN D & BONE DENSITY: WHAT WOMEN SHOULD KNOW
You can consume plenty of calcium, but without adequate vitamin D, your body has a harder time absorbing and utilizing it for healthy bone mineralization.
Vitamin D is a fat-soluble vitamin that also functions like a hormone. Your body can make it:
SUNLIGHT → SKIN → LIVER → KIDNEYS → ACTIVE VITAMIN D
The liver converts vitamin D to 25-hydroxyvitamin D [25(OH)D], the form typically measured on bloodwork. The kidneys then help convert it to its active form, calcitriol.
WHAT LEVEL SHOULD WE LOOK FOR?
The NIH considers 20 ng/mL or greater adequate for most healthy individuals. When focusing on bone density optimization, we often prefer levels comfortably above the minimum.
For patients with osteoporosis, AACE recommends at least 30 ng/mL, with 30–50 ng/mL preferred. [1]
WHY DOES IT MATTER?
Vitamin D helps support:
Calcium and phosphorus absorption
Normal bone mineralization
Calcium and PTH regulation
Muscle function and fall prevention
WHERE DO WE GET IT?
Sun exposure, fatty fish, egg yolks, UV-exposed mushrooms and fortified foods.
Sun production varies based on season, latitude, skin pigmentation, age and time outdoors. For those of us living through northern winters, sunshine alone may not always be enough.
THE BIG PICTURE
Vitamin D is only one piece of bone density optimization. Protein, calcium, magnesium, resistance training, weight-bearing exercise, hormonal health and overall nutrition matter too.
In functional and lifestyle medicine, we're not only asking, "Are you deficient?"
We're asking, "Are we creating the environment needed to build and preserve strong bone?"
REFERENCES
1. Camacho, P. M., et al. (2020). AACE/ACE clinical practice guidelines for postmenopausal osteoporosis. Endocrine Practice, 26(Suppl 1), 1–46.
2. NIH Office of Dietary Supplements. Vitamin D: Fact Sheet for Health Professionals.
3. Demay, M. B., et al. (2024). Vitamin D for the prevention of disease. Journal of Clinical Endocrinology & Metabolism, 109(8), 1907–1947.
Need your serum vitamin D checked? We offer in-house testing for $33.22 + draw fee.