Vitamin D Deficiency

True or false: the best source of vitamin D is healthy whole foods. Answer? It’s actually false! While vitamin D is critically important for so many components of our health, it’s actually not too easy to find naturally in many foods. Because of this, many people end up deficient in vitamin D.

So what happens when you don’t get enough? We’re getting into the D-ficiency discussion below – what causes ? What are symptoms? What are optimal vitamin D levels? And how much vitamin D per day should you take?


In general, results from lack of sun exposure, requiring more vitamin D than you take in, or the inability of the body to synthesize vitamin D due to other underlying disease. Here are the primary causes of :

Lack of Sun Exposure

  • Living in Northern Climates or Higher Latitudes: Except during the summer months, the skin makes little if any vitamin D from the sun at latitudes above 37 degrees north, which includes about two-thirds of the United States, basically anything north of Arizona, Texas, or North Carolina.
  • Excessive Use of Sun Blocking Measures: while sun blocking measures like sunscreen, sun hats, and shade umbrellas are great for preventing skin damage, they block the very rays that provide the vitamin D that our bodies need. While we certainly want our skin to stay healthy, you might consider the length and intensity of sun exposure and weigh the cost/benefit of whether to block those rays in instances of light and brief sun exposure.
  • Spending a Lot of Time Indoors: If your vitamin D status is at a healthy level, just 10 minutes of skin exposure daily (including most of the body, arms, legs, hands, and face, can maintain healthy levels of vitamin D. Note that this daily time requirement increases from 10 minutes to 1 hour if wearing SPF 15 sunscreen.
  • Darker Skin Pigmentation: Those with a darker skin pigmentation simply don’t take in as many of the sun’s rays. In fact, skin of certain cultures with intense sun exposure evolved this way for that very reason!

Higher Vitamin D Requirements

  • Breastfeeding: In the case of vitamin D, babies take what they need from mama and leave the rest. That means that if mama doesn’t have enough vitamin D for both of them, she’ll be left deficient. In order to have enough for both, it is recommended that breastfeeding women have 6400 IU daily of vitamin D.
  • Old Age: The elderly generally require more vitamin D for bone health, immune health, and a variety of other functions. They may also be less efficient at converting vitamin D, which puts this population at a higher risk of deficiency.

Underlying Conditions

  • Obesity: There has long been a correlation between low vitamin D status and excess weight, and for years it was unknown which one caused which. Since Vitamin D is stored in fat cells, recent research has demonstrated that higher stores of body fat can decrease the accessibility of vitamin D for other cells and tissues.
  • Fat Malabsorption: As vitamin D is fat soluble, those with difficulty digesting fat are at a higher risk of inability to properly absorb vitamin D.
  • Inflammatory Bowel Disease: As inflammatory bowel disease (IBD) can inhibit proper absorption of nutrients (a process that generally occurs in the intestines), it has been linked to .
  • Genetic Mutations: Many of us have genetic mutations that we aren’t even aware of, but certain mutations may affect how our bodies absorb nutrients. Just as the MTHFR mutation can affect the absorption of folic acid, the VDR gene mutation can impact the body’s ability to convert or use vitamin D.
  • Chronic Kidney Disease or Liver Problems: As the kidneys and liver are involved in the conversion and assimilation of vitamin D into the body, complications with these organs often lead to a .


Of course, the best way to determine whether you are deficient in vitamin D is to get your levels tested. You can request testing through your provider or find it through a third party relatively inexpensively. Your lab will likely have a reference range, but a generally accepted optimal range is 32-80 ng/mL.


If testing is unavailable to you, the following are some common symptoms to be aware of:

  • Immune deficiencies—getting sick often
  • Fatigue/tiredness
  • Bone loss
  • Muscle aches
  • Poor wound healing
  • Hair loss
  • Mood imbalances


While can be treated through natural sources of vitamin D like sun and certain plant and animal foods, practitioners typically recommend supplementation to ensure that the deficiency is filled before transitioning to a maintenance dose of vitamin D. However, for completeness, we’ll touch on all sources of vitamin D:


Vitamin D is synthesized in the skin following UVB exposure.


Plant foods contain vitamin D2 (ergocalciferol) which must be converted into the active form to be used by the body. Unfortunately, this conversion rate is not always reliable or efficient. Animal foods contain vitamin D3, which is metabolized more efficiently as D3 than D2.

  • Plant Sources: Vitamin D2 is found in small amounts in mushrooms (about 15-20 IU/cup).
  • Animal Sources: Vitamin D3 is found in cod liver oil (400 IU/tsp), salmon (450 IU/3 oz.), mackerel (500 IU/3 oz.), sardines (25 IU each), and egg yolk (40 IU/yolk). These sources are much richer and already contain the active form. However, they are unavailable to those following a vegan or vegetarian diet.


There are a wide range of supplements available, but many contain the less absorbable form of D2, or fail to include the necessary cofactors or “helper nutrients” needed for the body to properly absorb and use vitamin D. D3+K2 Complex combines vegan sources of vitamin D3 and vitamin K2 along with fermented K1, plus an organic food complex of shiitake mushroom mycelia, camu camu berry, collard greens, spinach, parsley, and cruciferous sprouts.

How much Vitamin D Per Day Do You Need?

There’s no one-size-fits-all answer to the question, how much vitamin D per day do I need? This is because the amount you need depends on your individual situation – your needs, your environment, and your current levels.

Research suggests that optimal serum vitamin D levels should be in the range of 32-80 ng/mL. Therefore, if you are at the low end or below this range, your needs are much higher than if you are on the higher end of the range and just looking to maintain. They are also higher if you happen to live in a northern climate or have a desk job that keeps you indoors away from sunlight most days of the week. In addition, you may want to increase your vitamin D heading into seasons of higher incidence of illness for a boost to the immune system.

In terms of amount per day as a maintenance dose (once levels are well within the optimal range), we often look to the recommended daily allowance (RDA). However, the RDA for vitamin D is one of the most hotly contested recommendations. While the RDA suggests 600 IU or 15 mcg for adults age 19-70 and 800 IU or 20 mcg for adults over age 70, most experts recommend higher levels of 1000-2000 IU/day or more.

One capsule of our D3 + K2 Complex offers 2000 IU or 50 mcg of D3 alongside 120 mcg of K1, 100 mcg of K2, and 45 mg of Vitamin C for optimal absorption. This dose can act as an effective maintenance dose and can be safely combined with your multivitamin supplements.

You can also combine capsules for a short-term therapeutic dose if testing revealed a deficiency and your practitioner recommends a higher daily dose, or you can use only in certain seasons when needs are higher or sun exposure is limited.

3 Years ago