Do You Need a Vitamin D Supplement?

Wow, it is already November! For many people, it is that time of year when the sun disappears until springtime. This can actually lead to Vitamin D deficiency.

Vitamin D is known as the “sunshine vitamin” because it is produced in your skin in response to sunlight. Many people become vitamin D deficient in the winter due to lack of sunlight. Luckily, vitamin D can also be obtained through supplements and certain foods.

Here are some reasons why you may want to consider taking a vitamin D supplement:

Vitamin D is important for bone health

Vitamin D promotes calcium absorption in your gut which helps maintain adequate blood levels. Thus, insufficient levels of vitamin D lead to low levels of calcium. Osteoporosis is a common consequence of long-term calcium and vitamin D insufficiency. Osteoporosis is characterized by low bone density that increases the risk for bone fracture. Other risk factors for osteoporosis include being female, increasing age, smoking, alcohol use, certain medications, thin frame, and family history. Osteoporosis is far less common in men but still certainly possible. It is really important for aging women to make sure they are getting adequate amounts of calcium and vitamin D.

Vitamin D could affect cancer risk

There is strong laboratory and animal evidence that vitamin D plays a role in the prevention of colon, prostate, and breast cancers. Research is still needed to determine whether vitamin D inadequacy in particular raises cancer risk or if  greater exposure to vitamin D is protective (source: National Institutes of Health). So, nothing set in stone yet but still very interesting.

Vitamin D could help ward off other diseases

There is also existing research that suggests that vitamin D helps reduce the risk of developing multiple sclerosisheart disease, and the flu.

Who is at risk for vitamin D deficiency?

  • People who get inadequate sunlight (in particular, those who are homebound or always wear long clothing)
  • Breastfed infants, vitamin D requirements usually cannot be met by human milk alone
  • Older adults, more likely to spend less time outdoors and do not absorb through skin as well
  • People with dark skin
  • Those who have undergone gastric bypass surgery (small intestine does not absorb as well)

A blood test can diagnose vitamin D deficiency but is not usually performed on a routine basis if you are otherwise healthy.

How much vitamin D do I need?

For most adults, 600 International Units (IU) is the recommended daily amount. In older adults (>70 years old), the recommended amount is 800 IU. Vitamin D supplements can be easily found over the counter.

Vitamin D rich foods

Want to get your vitamin D through diet? There are many great foods rich in vitamin D.


Food IUs per serving Percent DV
Cod liver oil, 1 tablespoon 1,360 340
Swordfish, cooked, 3 ounces 566 142
Salmon (sockeye), cooked, 3 ounces 447 112
Tuna fish, canned in water, drained, 3 ounces 154 39
Orange juice fortified with vitamin D, 1 cup (check product labels, as amount of added vitamin D varies) 137 34
Milk, nonfat, reduced fat, and whole, vitamin D-fortified, 1 cup 115-124 29-31
Yogurt, fortified with 20% of the DV for vitamin D, 6 ounces (more heavily fortified yogurts provide more of the DV) 80 20
Margarine, fortified, 1 tablespoon 60 15
Sardines, canned in oil, drained, 2 sardines 46 12
Liver, beef, cooked, 3 ounces 42 11
Egg, 1 large (vitamin D is found in yolk) 41 10
Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV) 40 10
Cheese, Swiss, 1 ounce 6 2

Many great, healthy options!

I know I will not be seeing much sun this winter in my part of the world so I will be taking a vitamin D supplement. Will you?

Disclaimer: Information contained in this post should not be substituted for medical advice. If you think you are having a problem, contact your own provider who knows your health history.