.jpg)
Vitamin D Deficiency and Some Things You Should Know
- Happy Spurling, CFMC, CNHP, CNC, & BCHHP
- Dec 30, 2025
- 3 min read
Many people are told that they are deficient in vitamin D, however, traditional supplementation may not be the best response and many people may not be truly deficient. Sources of vitamin D include sunlight, foods, fortified foods, and supplements.
The body synthesizes vitamin D from sunlight. Spending at least 15 minutes outside everyday is sufficient to receive adequate vitamin D. Food sources that naturally contain vitamin D include cod liver oil, salmon, swordfish, tuna fish, sardines, beef liver, and egg yolk. Some foods, like orange juice, milk, plant milks, and cereals, are fortified with synthetic vitamin D.
Supplements can also be used to increase vitamin D, but there are risks to this approach. Vitamin D should be taken with the cofactors necessary to process it, otherwise, these other nutrients are depleted by high doses of vitamin D. Depletion of these cofactors can lead to many symptoms, from blood sugar dysregulation to heart palpitations. These cofactors are needed to put the vitamin D to use, so without them vitamin D storage will increase, but available vitamin D is not likely to become sufficient.
The cofactors for vitamin D are retinol (vitamin A), magnesium, vitamin K2, omega 3 fatty acids, boron, zinc, and calcium. The most important of these are magnesium, retinol, and vitamin K2. Including these nutrients increases bioavailability and prevents an overload of stored vitamin D. Foods that naturally contain vitamin D are also a good source of these cofactors, making natural whole foods the best way to increase your vitamin D. Whole food supplements are a better option when adequate amounts cannot be sourced from the diet and sun exposure.
These cofactors not only make vitamin D more absorbable and prevent overload, but they also have a synergistic effect. “Vitamin D supplements combined with vitamin A [are] three times more effective in increasing blood levels as taking a vitamin D supplement on its own.” A similar effect happens when combined with each of the other cofactors.
There are two different forms of vitamin D, D2 and D3. Vitamin D2 is the form that is present in plants and fungi and is most common in fortified foods. Vitamin D3 is the form that occurs in animals and humans. Vitamin D3 is most effective at increasing blood levels of vitamin D. Vitamin D2 is metabolized by the liver and converted to D3.
The most common lab that is used to assess vitamin D levels is 25-hydroxy vitamin D, which is the storage form of vitamin D. A recent study shows that there is no benefit to having a 25-hydroxy vitamin D level above 20 ng/mL. This is contrary to previous beliefs, so many people with diagnosed vitamin D deficiencies may not actually be deficient.
The active form of vitamin D can also be tested, but this is a less common test, called 1,25-hydroxy vitamin D. This test shows a more important level by indicating how much vitamin D is actually available for use.
It is also important to note that 25-hydroxy vitamin D levels fluctuate throughout the year based on sunlight exposure during each season. Storage vitamin D levels tend to be the highest at the end of the summer, then they drop throughout the winter and hit their lowest point in early spring. This reflects how the body maintains sufficient active vitamin D throughout the darker seasons. Some people who have been diagnosed with deficient vitamin D may have been tested in the late winter to early spring, when their storage is low, but their active vitamin D is sufficient.
High doses of any isolated vitamin with inadequate amounts of its cofactors can lead to deficiencies and health complications. When it comes to vitamin D, sunlight and whole food animal sources, either dietary or supplemental, are the best choices to increase vitamin D levels in people who are truly deficient.
For a personalized supplement and nutrition plan, schedule an appointment with Renewed Hope Nutrition.
Comments