Vitamin D

Vitamin D has been emerging as a wonder vitamin. Studies show that it not only builds strong bones and teeth, but also reduces the risk of certain cancers and diabetes, boosts the immune system, lowers blood pressure, and supports a healthy nervous system (lowered risk for multiple sclerosis).

The best way to obtain vitamin D is through sun exposure without sunscreen. These levels can last for months, but by early spring most people in North America have used up their stores. Here are some tips to keep in mind as you try to maintain adequate levels of vitamin D throughout the year.

The length of time required for producing optimal levels of vitamin D from sunshine varies depending on numerous factors. The stronger the sun (closer to the equator) the less time you need. The time of year plays a factor not only because of the clothes you may or may not be wearing, but because of the angle of the sun. The darker your skin, the more time you need. But over-exposure can increase your risk of skin cancer.  To calculate the length of time you should expose your skin to the sun, read this article from Sunfriend.

If you need to supplement with vitamin D (which is a good idea especially during the winter), be sure to take D3, cholecalciferol, the more bioavailable form, as opposed to D2. Read the labels of D-fortified foods. If it doesn’t specify D3, it’s probably D2 which is cheaper. Remember, vitamin D, a fat soluble vitamin, is stored in the body. The excess is not eliminated meaning it’s possible to get too much, which can be toxic. Blood tests at your annual exam can determine if you have good levels, but ask for the 25(OH)D test, Not the 1,25(OH)₂D test. I know they sound very similar but they’re not. The 25(OH)D test is the only one that will tell you whether you’re getting enough vitamin D. If your health insurance won’t cover it, check out these other options.

Speaking of fat, a new study published in the Journal of the Academy of Nutrition and Dietetics showed the importance of eating fat when taking vitamin D supplements. A recent article (below) in the AHHA (American Holistic Health Association) reviews the findings:

Dietary Fat Helps Boost Vitamin D Absorption 

The sunshine vitamin just found a new friend—dietary fat. A new study from Tufts University researchers has found that taking vitamin D supplements along with a meal containing fat boosts the absorption of vitamin D significantly. Published in the Journal of the Academy of Nutrition and Dietetics, the study divided 50 healthy older men and women into three groups; one group took vitamin D while consuming a fat-free breakfast, while the second and third groups took vitamin D while consuming a breakfast that was 30% fat by calories. The ratio of monounsaturated to polyunsaturated fats was 1:4 in the meal consumed by the second group, whereas that ratio of dietary fat was reversed in the meal consumed by the third group (4:1). All of the participants took a single, 50,000 IU dose of powdered vitamin D-3 with their breakfast for this one-day study. Here’s what the researchers discovered:

  • 12 hours after taking the vitamin D supplement, participants who ate a fat-containing breakfast experienced a 32% increase in vitamin D absorption compared to those in the fat-free group.
  • Participants who ate a fat-containing breakfast experienced a 40% increase in vitamin D absorption after 10 hours and a 25% increase after 14 hours, compared to the fat-free group.
  • The absorption rates of the two groups who consumed a fat-containing  breakfast did not differ significantly at any point. Hence, the ratio of monounsaturated to polyunsaturated fats did not affect vitamin D absorption.

The study sheds an important light on how diet affects vitamin D absorption—an issue that previously has not been well understood.

Source: Journal of the Academy of Nutrition and Dietetics

Dawson-Hughes B, Harris SS, Lichtenstein AH, Dolnikowski G, Palermo NJ, Rasmussen H. “Dietary fat increases vitamin D-3 absorption.“, Journal of the Academy of Nutrition and Dietetics, 2015 Feb;115(2):225-30. doi: 10.1016/j.jand.2014.09.014.

© Bobbi Mullins 2011, All rights reserved. FOOD FITNESS FAITH™