Sunshine vitamin

The sunshine vitamin has been one of the most controversial vitamins of recent times. The primary reason for this relates to questions of deficiency and toxicity. Or, simply put, how much is too much?

What is it?

Vitamin D is a fat-soluble vitamin which has variants which are sterol (cholesterol-like) substances. No vitamin requires more whole-body participation that vitamin D. The skin, bloodstream, liver, and kidneys all contribute to the formation of fully active vitamin D. The process starts with the skin cells and sunlight. Vitamin D is known as the sunshine vitamin because it is actually manufactured in the human skin when in contact with the ultraviolet light in the sun’s rays. Calcitriol, also known as vitamin D3, is considered by many researchers to be the only truly active form of vitamin D. Winter, cloud cover, smog, and darkly pigmented skin reduce the body’s production of vitamin D.

Functions

Vitamin D works with the parathyroid hormone for calcium metabolism. Functionally, vitamin D works like a hormone and it is closely related structurally to the body hormones estrogen and cortisone.  It is produced in one part of the body to affect the bones; in fact, vitamin D regulates bone formation. The parathyroid produces active vitamin D3 when the body needs it. If vitamin D is low, blood levels of calcium and phosphorus decrease, and the body pulls these minerals from the bones, potentially leading to demineralized, weak bones.

Although it may function and have a structure similar to a hormone, it is nevertheless a vitamin. The reason this is important is that knowing what something is has consequences for its intake requirements and how it works in the body. Attempts to promote Vitamin D nutrition are hindered by alarmist responses justifiably associated with the widespread administration of any hormone. Vitamin D is a vitamin in the truest sense of the word, because insufficient amounts in the diet may cause deficiency diseases.

Deficiency 

Vitamin D deficiency has been associated with chronic pain, chronic kidney disease, Crohn’s disease, hyperparathyroidism, osteoporosis, osteomalacia, and rickets. Myopia and loss of hearing may develop from vitamin D deficiency because of the vitamin’s influence on eye muscles and from loss of calcium in the ear bones. One of the current theories of multiple sclerosis is that it may be influenced by low vitamin D levels in puberty.

New research at the University of Calgary has concluded that virtually all Canadians are vitamin D deficient during some part of the year when sunlight exposure is scarce.

Supplementation

Supplementing vitamin D improves calcium absorption and reduces bone loss. The skin absorbs the highest levels of vitamin D through prolonged sun exposure before the body has adapted through pigmentation (tanning), which protects the deeper layers where the vitamin D is synthesized. In other words, the darker your natural skin colour, the more time you  need to spend in the sun to get sufficient amounts of vitamin D.

Requirements

The Vitamin D Council recommends 5000 IU daily for adults, 1000 IU for children. Get you blood levels checked. Ask for a copy of your blood report. The Vitamin D Society says we should strive to maintain between 100 and 150 nmol/L in our blood.