Did you know that Vitamin D is a hormone? In the body, vitamin D, also known as the sunshine vitamin, is dependent on sun exposure. The UVB rays in sunlight convert cholesterol to vitamin D in the skin. However, as the dangers of UV radiation have become better understood, we are spending less time in the sun and are using sunscreen. Sunscreen protects from the harmful UV rays but it also blocks the skin’s conversion of Vitamin D to its active form (D3). A sunscreen with sun protection factor (SPF) 30 can reduce the body’s ability to synthesize vitamin D by 95%. Additionally, after age 20, our skin becomes less and less efficient at converting this vitamin to its active form. Since vitamin D is not found in most foods (except fish oil and fatty fish), deficiencies are not uncommon. Recent studies have suggested that up to 50% of adults and children worldwide are vitamin D deficient.
Adequate vitamin D intake is important for the regulation of calcium and phosphorus absorption, maintenance of healthy bones and teeth, and is suggested to supply a protective effect against multiple diseases and conditions such as cancer, type 1 diabetes and multiple sclerosis.
Role of Vitamin D
- Maintain the health of bones and teeth
- Support the health of the immune system, brain and nervous system
- Regulate insulin levels and aid diabetes management
- Support lung function and cardiovascular health
- Influence the expression of genes involved in cancer development.
Vitamin D Facts
- A fair-skinned person with full body exposure to the sun can synthesize up to 20,000 IU of vitamin D3 in 20 minutes.
- Vitamin D deficiency is common, especially in the elderly, infants, people with dark skin and people living at higher latitudes or who get little sun exposure.
- Vitamin D deficiency has been seen in up to 80% of hip fracture patients
- 800 IU of vitamin D per day decreases the risk of falls in the elderly and reduces their risk of fracture by 20%.
- The metabolism of vitamin D may be affected by some medications, including barbiturates, phenobarbital, Dilantin, isoniazid and statin drugs.
Vitamin D and Cancer
To understand cancer at a cellular level you must understand the role of apoptosis. Apoptosis (“ay-pop-toe’-sis”) means “programmed cell death”. A cell evolves through normal cell division, lives its normal life span (which varies depending on cell type), then undergoes apoptosis (death) to make way for new cells and the regeneration of tissues in the body. Decreased apoptosis means the cells live longer because they don’t die when they are supposed to. This is the essence of cancer.
In a rapidly growing cancer, apoptosis has turned off, the cells divide and increase without dying and then take over the neighboring normal cells. Cancer cells make an anti-apoptotic protein called Bcl-2. There is more Bcl-2 protein surrounding cancer cells than normal cells.
High and balanced levels of hormones are protective. As we age, this protective effect is lowered due to the declining levels of hormones. Specifically, high levels of certain hormones (like estrogen in women and testosterone in men) will lower the production of Bcl-2. Vitamin D also lowers Bcl-2.
Vitamin D kills cancer cells (while preserving normal cells) in at least four different ways.
- lowers the production of an inflammation enzyme (COX-2)
- raises the production of a tumor suppressor (15-PGDH)
- lowers the activity of aromatase, an enzyme that increases the production of a harmful estrogen metabolite
- lowers the production of Bcl-2
Vitamin D has been shown to lower Bcl-2 in a variety of cancers, including breast cancer, prostate cancer, and colorectal cancer. In fact, due to its anti-Bcl-2 activity, it is even being studied as a treatment for several other cancers.
Adequate Vitamin D
Vitamin D intake can be measured in two ways: in micrograms (mcg) and International Units (IU). One microgram of vitamin D is equal to 40 IU of vitamin D
Most laboratories reference ranges for the level of active vitamin D (D3) are from 30 to 100. However, an optimal range should be above 60. This optimal level can not be obtained without taking a vitamin D supplement.
Is it possible to take too much vitamin D? It is possible but difficult. Vitamin D toxicity is unlikely at daily intakes below 10,000 IU/day. The main consequence of vitamin D toxicity is a buildup of calcium in your blood (hypercalcemia), which can cause poor appetite, nausea and vomiting. Weakness, frequent urination and kidney problems also may occur. Treatment includes stopping excessive intake of vitamin D.
A daily dose of 5,000 IU or a weekly dose of 50,000 IU of D3 (the active form) is recommended . Whichever way it’s supplemented, it is important to get vitamin D levels checked. And – don’t settle for being barely in the range: Be optimal at 60 and above.
Vitamin D is one of the simplest and most effective ways to help protect normal cellular function. It is also an incredibly inexpensive way to maintain health.