Vitamin D
Many experts consider Vitamin D to be a hormone: the definition of a hormone is something that is produced at one place of the body but carries out its function in another part of the body (such as thyroxine for example that is produced in the thyroid but works in all the cells of the body).
Role of Vitamin D in the body
Most of the body's Vitamin D should be produced in the skin by the action of sun onto the skin's cells. Its role in the body is to cause absorption of calcium from the gastrointestinal system into the blood stream and then it tries to directly increase the deposition of calcium into the bones.
Most of Vitamin D is manufactures on our skin, but we can get some dietary Vitamin D from fatty fish (salmon, tuna etc), egg yolk and cheese.
Without enough Vitamin D, the body cannot absorb dietary calcium (calcium in the absence of vitamin D just stays in the gastrointestinal system is and excreted). As a result, not only Vitamin D cannot "inject" the absorbed calcium in the bone, but the body will try to replenish the calcium requirements from the bone by excreting calcium from the bone matrix into the circulation, thus causing a net loss of calcium from the bone.
However Vitamin D benefits numerous other important functions of the body like immune system and muscle function. By supporting the immune system, we are able to fight better any inflammation caused by either toxins, bacteria or viruses. Thus by preventing common cold for example and maintaining healthy muscles, you are preventing fatigue and you are lifting your energy levels.
Function of Vitamin D
- Help maintain normal bone, in terms of QUANTITY (i.e. how much bone we have) as well as QUALITY (i.e. the bone matrix of the bone is healthy with good resilient architecture)
- Vitamin D receptors are found in muscles, and it appears to help with muscle strength
- Helps with periodontal disease and health of gums
- Immune system support an regulation
- Improvement of insulin functioning and hence better control of glucose/sugar
Recommended dose
There is no recommended dose of Vitamin D as this varies from each individual. The aim is to have blood (plasma) level of Vitamin D between 40 and 60 ng/mL. Some people achieve this by taking 1000IU to 2000IU daily, while some others require as much as 5000IU per day. Thus the recommended dose of vitamin D is the dose that is required to maintain adequate blood levels of Vitamin D, and this dose is different for each one. You will need to speak with your family doctor in order to get specific guidance.
Vitamin D Deficiency
Vitamin D deficiency could lead to:
- Increased bone loss (i.e. osteoporosis) and bone of lesser quality (i.e. more fragile bone that breaks easier)
- Weaker muscles and increasing risk of falls in the elderly
- Weaker teeth (due to poor absorption of calcium and phosphate)
- Tendency towards depression
- More frequent infections (as it plays a role in appropriate activation of immune system)
- Worse outcome of autoimmune conditions
Learning From Science
- People with periodontal disease appear to get benefit from Vitamin D supplementation
- Autoimmune conditions (such as Psoriasis or Rheumatoid Arthritis) show clinical improvement once Vitamin D reach therapeutic levels
- Vitamin D supplementation, appears to strengthen muscular tone, and as a result it reduces the likelihood of falls in people over 75 years old
- Young babies from mothers who are breastfeeding and have low vitamin D levels, are more likely to develop soft/rickety bones, a condition called Ricketts. This effects ameliorates if the mother has sufficient levels of Vitamin D