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Vitamin D - When to test?

Content by: Sarah Bigbee, RD

Vitamin D can be produced within the body, as well as obtained from diet. Read more about when to test vitamin D levels, and how to maintain adequate levels.

💡 Features: Sunshine Vitamin, UV Rays, Winter Blues, SAD, Supplement, Vitamin D Test
🏷 Tags: Article, Blog, Handout, Download

Vitamin D - When to test?


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Vitamin D is a fat soluble vitamin that plays many important roles in our health and well being. It helps the body absorb calcium to ensure strong bones, supports immune health, assists the break down and use of glucose and reduces inflammation. Vitamin D can be produced through UV exposure (sunshine) or obtained through consuming foods, beverages and/or through supplementation. The ability to make Vitamin D through the skin depends on UV exposure, clothing choices, sunscreen use and even the pigmentation of skin. Since there is more opportunity for sunshine exposure in the summertime, Vitamin D levels tend to be higher. The winter months bring less exposure to UV rays, due to shorter days and weaker rays which can cause lower levels of Vitamin D.

These seasonal shifts create a higher risk for low Vitamin D levels and may offer benefits from two Vitamin D tests per year. Vitamin D Testing determines baseline and offers insight for any intervention. The two best times to test are the start of spring when days begin to lengthen and the end of summer.

A spring test will give a Vitamin D level that represents the sustained availability through the winter. This gives professionals the opportunity to offer summer practices that boost Vitamin D levels. If getting enough natural sunshine is limited, Vitamin D dietary options or supplementation may be advised.

Having Vitamin D levels checked at the end of summer, or a bit later as fall begins, indicates the need for Winter practices. If Vitamin D value is within normal limits, there is little need for supplementation. When Vitamin D levels are on the lower side of within normal limits, consider a supplement to support the Winter months with vitamin D. Always discuss supplement needs with a Physician. And, it is still beneficial to understand foods and beverages that are high in vitamin D to include in the diet.

Achieving adequate Vitamin D levels helps in living healthier, happier lives. Below, find a list food sources with Vitamin D. Many of the food items with naturally occurring Vitamin D are seafood or organ meats, which may be pungent in taste.

Good Sources of Vitamin D:
🥩 Beef Liver
🍽️ Cod Liver
🥚 Eggs including the Yolk
🥣 Fortified Cereal or Grains
🥛 Fortified Dairy (Milk, Yogurt)
🥤 Fortified Juices
🌰 Fortified Plant Milks (Almond, Cashew, Oat, Soy )
🍣 Salmon
🍥 Sardines
🐟 Swordfish
🍣 Tuna Fish

Next Steps:

1. Check here for a fun client handout explaining how to improve vitamin D levels:

2. If your client is interested in home testing check out the Thorne home testing kit for Vitamin D levels:

3. If your client needs supplementation SoulFIRE Health Professional Partner, Thorne HealthTech, offers multiple Vitamin D supplements depending on your clients preferences:
· Vitamin D-1,000:
· Vitamin D + K2 Liquid:
· Vitamin D Liquid:

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