The most critical bone-building nutrients are: Calcium (the primary mineral in bone), Vitamin D3 (essential for calcium absorption), Vitamin K2 as MK-7 (directs calcium into bones and away from arteries), Magnesium (activates vitamin D and supports bone structure), Boron (enhances calcium and magnesium retention), Zinc (supports bone-forming cells), Silicon, Strontium, Phosphorus, and vitamins C, B12, and folate. No single nutrient works in isolation — they form an interconnected team.

Most adults need 1,000–1,200 mg of calcium per day from a combination of food and supplements. However, more is not always better — excessively high calcium intake (especially from supplements alone without K2 and D3) can contribute to arterial calcification. Dr. Brown recommends getting as much calcium as possible from food sources, and using supplements only to bridge the gap — always paired with vitamin K2 and D3.

For most people in North America, especially those who spend limited time outdoors, a vitamin D3 supplement is strongly recommended. Vitamin D is essential for calcium absorption — without adequate vitamin D, you absorb as little as 10-15% of the calcium you eat. A blood level of 40-60 ng/mL (100-150 nmol/L) is generally optimal for bone health. Dr. Brown recommends testing your vitamin D level and supplementing accordingly.

Top food sources of calcium include: sardines and canned salmon with bones, leafy greens (collards, kale, bok choy), fortified plant milks, white beans, almonds, tahini, and dairy products. Note that the alkaline-forming nature of the food matters too — calcium from alkaline-forming vegetables like kale is very well absorbed, while high-sodium processed foods cause calcium to be lost in urine.

Dairy is a good source of calcium, but it is not required for strong bones. Many populations with very low dairy intake have excellent bone health due to diets rich in other calcium sources and alkaline-forming foods. More important than the source of calcium is avoiding bone-depleting factors: excess sodium, acid-forming diet, vitamin D deficiency, and K2 deficiency. Dr. Brown’s program focuses on the whole nutritional picture, not just one food group.

Vitamin K2 (especially the MK-7 form) activates a protein called osteocalcin, which is responsible for binding calcium to the bone matrix. Without adequate K2, calcium can be absorbed but not properly deposited in bones — and may instead accumulate in soft tissues and arteries. K2 works synergistically with vitamin D3 and calcium. Best food sources include natto (fermented soy), aged cheeses, and egg yolks; supplementation is often needed for therapeutic amounts.

Adequate protein is essential for bone health — bones are approximately 30% protein by weight. Too little protein leads to bone loss; however, very high intake of certain animal proteins without balancing alkaline-forming vegetables may increase calcium excretion. The key is getting adequate protein from a variety of sources (both animal and plant) within the context of an overall alkaline-forming diet rich in fruits and vegetables.