Vitamin D is a fat-soluble vitamin that plays a role in many important body functions. Sometimes this vitamin is known as the sunshine vitamin—not vitamin C—as you absorb it through the skin from direct sunlight.
The term “vitamin D” refers to several different forms of this vitamin. Two forms are important in humans: Vitamin D2 and vitamin D3. Plants synthesize Vitamin D2. Humans in the skin synthesize Vitamin D3 when they expose it to ultraviolet B rays from sunlight. Foods, which say fortified with vitamin D, will be either D2 or D3. Most recommend D3.
Purpose: Vitamin D is important in helping the body absorb calcium. It is also necessary in the utilization of phosphorous. Also known as Calciferol, it promotes strong bones and teeth, prevents rickets, supports muscle and nerve function, and, some studies have shown, helps prevent osteoporosis.
Larger doses of vitamin D appear to help, allergies, back pain, fibromyalgia, heart disease, mental health, multiple sclerosis, skin cancer, and type 2 diabetes.
Sources: Very few foods in nature contain vitamin D. Fortified milk and cereals, eggs, tuna, fish-liver oils, and sun exposure all help the body obtain vitamin D. Mushrooms are a non-animal product source of vitamin D. That’s funny because mushrooms are grown in the dark.
Recommended Daily Allowance: Men and women aged 19-50 should consume at least 200 IU of vitamin D on a daily basis. People over the age of 50 should consume at least 400 IU daily, as the body’s ability to convert sunlight to vitamin D decreases with age. My multivitamin has 60 mg, which according to my calculations is 1200 IU’s.
Research shows that as little as 10 minutes of exposure would be enough to prevent deficiencies.
While too little vitamin D can lead to weakened bones and an increased risk of fractures.
Excess vitamin D can cause the body to absorb too much calcium, leading to increased risk of heart attack and kidney stones. Too much vitamin D can cause nausea, vomiting, poor appetite, constipation, weakness, and weight loss. Prolonged exposure to too much vitamin D can lead to health problems and toxicity.
If you take, antacids, some cholesterol lowering drugs, some anti-seizure medications, or steroids, know that they all interfere with the absorption of vitamin D.
There is controversy in the medical field on how much is adequate. The main reason most of us lack adequate vitamin D is that we aren’t soaking up enough sun. when the sun’s ultraviolet (UV) rays strike the skin, they stimulate our bodies’ production of vitamin D. Therein lies the problem. People are not outside as much. We drive to work in the dark and come home in the dark. Kids spend a great deal of time indoors. The elderly particularly stay indoors more. Recommendations are for more vitamin D such as 800 IU and for those getting no sunlight.
The ideal approach is to ask your doctor for a vitamin D blood test, which will eliminate the bulk of the guesswork — but not all of it. Because of individual differences in absorption and use, people may need to take differing quantities of vitamin D to achieve a healthy blood level. Make sure your doctor orders a “25-hydroxy vitamin D” test.
If you don’t currently have a significant deficiency and if during the summer, you spend a lot of time in the sun, with at least your arms and legs exposed, and you don’t cover yourself with sunscreen, you probably don’t need to take vitamin D supplements.