How does vitamin D help bones?
Written by
Tran Quang
Reviewed by
Prof. William Dalton, Ph.D.Vitamin D is the key to bone health with a straightforward role - it allows for calcium. When vitamin D is sufficient, you can get as much calcium as you want from your food. When vitamin D is low in your body, 50% or more of your dietary calcium is unavailable to your body. Vitamin D is a fat-soluble vitamin that has hormone-like qualities, regulating the transport of calcium across intestinal membranes. Adequate vitamin D is crucial for the mineralization process.
Calcium Absorption
- Activates calcium-binding proteins in intestinal walls
- Enables transport of calcium into bloodstream
- Increases calcium absorption efficiency by 30-80%
- Prevents calcium excretion through kidneys
Mineralization Regulation
- Maintains proper calcium-phosphate balance
- Directs mineral deposition into bone matrix
- Prevents soft tissue calcification
- Supports osteoblast cell function
Hormonal Signaling
- Regulates parathyroid hormone production
- Prevents excessive bone resorption
- Modulates immune response affecting bone
- Influences muscle function for bone loading
Calcium absorption ultimately relies on vitamin D status. The vitamin activates calcium transporters in the intestinal walls. Without it, no matter how much calcium someone eats, it will never be digested. I have witnessed clients fix these deficiencies, and calcium absorption doubles within weeks.
Sunlight exposure is a natural source that is the most effective of all. During midday, UVB rays help to convert cholesterol in the skin to previtamin D3. About 10-30 minutes of midday sun can provide 10,000-20,000 IU. Darker skin types require about three to five times longer. One's latitude and the season of the year are important factors associated with UVB availability.
Vitamin D can typically be found in dietary sources throughout the entire year, with the best sources offering either naturally occurring D3 (fatty fish like salmon) or synthetically added D2 (fortified foods like milk and cereals). Egg yolks are a minimal source of D. These can be consumed with healthy fats, such as avocado, to boost absorption.
Supplementation is necessary for a lot of people, especially for people living in northern latitudes, elderly people, or people with darker skin. Most people require D3 supplementation. Take 600-800 IU daily with meals containing fat for maximum absorption. Blood testing can show that levels fall within the ideal range of 30-50 ng/mL.
Consequences of deficiency can include impaired bone mineralization and reduced bone strength, which can lead to fractures. Vitamin D is essential for calcium to be properly incorporated into the bone matrix. In the absence of vitamin D, calcium would not be incorporated into the matrix. It would leave soft, weak bones with the same amounts of calcium. Adequate daily intake is necessary regularly throughout life to support bone mineralization.
Read the full article: 3 Essential Steps How Strengthen Bones
