Live Well Vitamins & Lifestyle Guide

Vitamin D

Vitamin D plays several key roles in your body. Most importantly, vitamin D helps your body absorb the minerals calcium and phosphorus from the food you eat.  

Vitamin D Uses

Vitamin D is quite important for people with osteoporosis. Studies show that calcium and vitamin D together can increase bone density in postmenopausal women. Vitamin D also helps with other disorders associated with weak bones, like rickets.

People who have low levels of vitamin D may need supplements. Vitamin D deficiencies are more common in those who:

• Are over 50
• Get very little sun exposure
• Have kidney disease or diseases that affect the absorption of minerals
• Have darker skin
• Are lactose intolerant
• Are vegan
• Are infants who are fed only breast milk

Vitamin D deficiency may cause hormone problems, muscle weakness and pain, and other symptoms.

Studies have found prescription-strength vitamin D lotions helpful in treating psoriasis. Vitamin D has also been studied for other conditions ranging from cancer prevention to high blood pressure, but the evidence is unclear.

How Much Vitamin D Do You Need?

The Institute of Medicine has set an adequate intake for vitamin D. Getting this amount of vitamin D from diet, with or without supplements, should be enough to keep your bones healthy.

• 200 IU (international units) a day for children and adults under 50
• 400 IU/day for ages 51-70
• 600 IU/day for ages 70 or over

Many experts think that these recommendations are too low, especially for people at risk of osteoporosis. Some suggest 800 IU to 1,000 IU of vitamin Da day for all adults over age 50. Ask your doctor how much vitamin D you need.

The recommended upper limit for vitamin D -- the most you can take safely -- is 2,000 IU a day for adults and 1,000 IU/ day for children over age 1. Amounts of vitamin D above this could be toxic.

Vitamin D Food Sources

The best source of natural vitamin D is sunlight. Just 10 to 15 minutes of exposure without sunscreen a couple of times a week usually gives you enough vitamin D.

Vitamin D is also naturally found in butter, eggs, and fish liver oils. Vitamin D is often added to fortified foods, too, such as milk and cereal.

Vitamin D Supplement Information

Vitamin D is available in tablets and capsules. It's also standard in multivitamins. A prescription-strength topical cream with vitamin D is used to treat psoriasis. Like any supplement, keep vitamin D supplements in a cool, dry place, away from humidity and direct sunlight.

Vitamin D is sold in two forms, vitamin D2 and D3. Vitamin D3 is preferable, since it has a stronger effect.

Vitamin D Warnings

• Side effects. At normal doses, vitamin D seems to have few side effects.
• Interactions. Vitamin D can interact with many medicines, such as drugs for high blood pressure and heart problems. If you take daily medicine, ask your doctor if it's safe for you to take vitamin D supplements.
• Risks. Signs of a vitamin D overdose include nausea, vomiting, weakness, constipation, and weight loss. High doses of vitamin D can also lead to disorientation and kidney and heart problems.