Vitamin D: Effectiveness, Benefits and Safety
updated August, 2016
What is Vitamin D?
Vitamin D is a steroid hormone, a group of fat-soluble prohormones, which encourages the absorption and metabolism of calcium and phosphorous. There are two major forms of vitamin D: D2 (ergocalciferol) and D3 (cholecalciferol).
People who are exposed to adequate of sunlight do not need vitamin D supplements because sunlight promotes sufficient vitamin D synthesis in the skin. Aim for 15 minutes in the sun without sunscreen! Expose your face, arms and hands at least twice a week. And wait to wash off the sun! It takes up to 24 hours to absorb vitamin D through the skin.
Vitamin D3 is produced naturally in human skin exposed to ultraviolet B light and occurs in some animal products, such as cod liver oil, and, in smaller amounts, in other fatty fish such as herrings, mackerel, sardines, and tuna. Vitamin D3 is the most common form found in dietary supplements and is the form generally used to fortify foods such as milk (which naturally contains a small amount of vitamin D3), orange juice, cereal and yogurt.
Why do we need Vitamin D? Vitamin D:
- Regulates the amount of calcium and phosphorous in the body, partly by controlling their levels of absorption
- Treats and prevents rickets in children and osteomalacia (bone softening) in adults
- Helps reduce inflammation in the airways caused by asthma
- Regulates the immune system
- Arms the immune system against infections
- May keep the brain working well in later life
- Is probably linked to maintaining a healthy body weight.
- Reduces the risk of developing rheumatoid arthritis in women.
- Can protect the body against damage from low levels of radiation
- Lowers risk of developing cancer
- Reduces risk for heart attacks, congestive heart failure, peripheral arterial disease (PAD), strokes, and the conditions associated with cardiovascular disease, such as high blood pressure and diabetes.
- Provides protection against Parkinson’s disease
- Lowers risk and severity of depression
- Reduces risk of allergy in children and adolescents
- Taken with calcium, vitamin D can help decrease post-menopausal bone loss and prevent osteoporosis (loss of bone density), as well as improve tooth retention in the elderly.
- Increases bone density significantly in girls ages 9 to 13
Approved Vitamin D Product List
An independent lab tested 21 Vitamin D supplements, but only 18 products passed. Three Vitamin D supplements were found UNSAFE for consumption due to incorrect labeling. These three are: