Bone Health Across the Female Lifespan

Bone health remains a dynamic, lifelong concern for women, affected by hormonal fluctuations, nutritional status, and age-related physiological shifts. The skeletal system requires consistent nutritional support to maintain optimal density, strength, and resilience throughout all life stages. Recognizing these critical needs, Momentous has developed the Women's Three, a precisely formulated trio of supplements designed to address the key micronutrient requirements that support skeletal integrity and metabolic health throughout a woman's journey.

This article outlines the key physiological and lifestyle factors that influence nutrient absorption and how to strategically leverage them for optimal results.

The Physiology & Key Considerations of Bone Health

Peak Bone Accrual (Adolescence to Early Adulthood)

The majority of skeletal mass is acquired during adolescence, with peak bone mineral density typically achieved by age 30. This phase is marked by high osteoblastic activity, dependent on sufficient dietary intake and hormonal regulation. Calcium and vitamin D are foundational during this window to support bone formation and matrix development. Research demonstrates that bone accrual during adolescence contributes to up to 90% of adult skeletal mass, with calcium and vitamin D playing rate-limiting roles in the mineralization process (Weaver et al., 2016).

Maintenance and Reproductive Years (30s to Early 40s)

During this relatively stable phase, bone turnover reaches equilibrium, but modifiable factors such as nutrient status, menstrual regularity, and physical activity; determine the preservation of bone mass. Women of childbearing age often experience suboptimal iron stores, especially those with heavy menstrual bleeding, higher physical activity levels, or dietary restrictions. From a mechanistic standpoint, iron deficiency can compromise collagen cross-linking and bone matrix quality through impaired hydroxylation of proline and lysine residues, indirectly affecting bone integrity even when calcium levels are adequate.

Perimenopause and Menopause (Mid-40s to 50s)

The perimenopausal transition is characterized by a steep decline in circulating estrogen, a hormone that modulates osteoclast and osteoblast activity. Loss of estrogen's inhibitory effect on bone resorption leads to increased osteoclastic activity and rapid reductions in bone mineral density, averaging 2–3% annually in the early postmenopausal period. This represents a critical window for targeted calcium and vitamin D supplementation, both to slow resorptive processes and maintain serum calcium balance in the context of decreased intestinal absorption that accompanies hormonal changes.

Postmenopausal and Later Years (60s and Beyond)

With aging, renal conversion of 25(OH)D to 1,25(OH)₂D (calcitriol) diminishes, impairing calcium absorption and exacerbating the risk of secondary hyperparathyroidism and osteoporotic fractures. Furthermore, reduced gastric acid production in older adults can limit absorption of certain calcium salts, making calcium dimalate, a highly bioavailable and pH-independent form, a superior option for women in this life stage.

The Women's Three: Clinical Rationale for Each Component

1. Iron+ (AM Dosing)

This formulation contains iron bisglycinate (a chelated, highly absorbable form of iron) combined with vitamin C to enhance non-heme iron absorption and a spectrum of B-complex vitamins (B2, B6, B12, folate) essential for erythropoiesis and methylation support.

Mechanism of Action: Iron is critical for hemoglobin synthesis and mitochondrial function. Vitamin C reduces ferric (Fe³⁺) to ferrous (Fe²⁺) iron, enhancing intestinal absorption.

Clinical Relevance: Iron deficiency is associated with fatigue, impaired cognitive performance, and decreased exercise tolerance. It may also indirectly affect bone health through anemia-related hypoxia.

2. Calcium (PM Dosing)

The bundle includes calcium dimalate, known for its superior absorption profile and reduced gastrointestinal side effects. It does not require a low-pH environment for dissolution and is less likely to interfere with the absorption of other minerals when spaced appropriately.

Mechanism of Action: Calcium serves as a structural component of bone and modulates signaling cascades that control osteoblast/osteoclast activity. Adequate intake is essential to suppress parathyroid hormone (PTH) and reduce bone resorption.

Clinical Relevance: Postmenopausal women with low calcium intake are at significantly greater risk of osteopenia and osteoporosis. Supplementation slows age-related bone mineral density loss and reduces fracture risk.

3. Vitamin D3 (PM Dosing)

Provides cholecalciferol (D3), the preferred form due to its higher potency and longer half-life compared to ergocalciferol (D2). When taken in the evening alongside calcium, it supports overnight bone remodeling and calcium homeostasis. A quick note on vitamin K: There’s a common belief that vitamin D3 must be paired with K2 to prevent arterial calcification. While vitamin K supports calcium metabolism, research doesn’t show a clear need for K2 supplementation in healthy individuals with balanced diets. Most people meet their needs through food, and the concern around D3 increasing calcification risk stems more from theory than consistent human evidence, thus the need for K2 supplementation is unwarranted.

Mechanism of Action: Vitamin D3 enhances intestinal absorption of calcium and phosphate, and exerts direct effects on osteoblast and osteoclast function.

Clinical Relevance: Deficiency is linked to decreased bone mineral density, increased fall risk, and impaired muscle function. Combined supplementation with calcium has shown to improve outcomes in both fracture prevention and musculoskeletal strength.

Optimized Nutrient Timing: Why Morning vs. Evening Matters

Iron+ in the Morning: Absorption of iron is maximized in a fasted state and is inhibited by calcium, making morning dosing ideal.

Calcium + Vitamin D3 in the Evening: Bone remodeling is most active during nocturnal hours, and pairing calcium with vitamin D3 supports better utilization during this window. Additionally, evening dosing aligns with chronobiological rhythms of parathyroid hormone and bone turnover markers.

Evidence-Based Support for Every Stage of a Woman's Journey

The Women's Three bundle is built on a foundation of clinical research, nutrient synergy, and physiological timing, offering a streamlined, comprehensive approach to supporting bone and metabolic health from adolescence through advanced age. By delivering iron, calcium, and vitamin D3 in their most effective forms and aligning with natural circadian rhythms, this protocol empowers women to take control of their skeletal health proactively, not reactively.