Also known as the “sunshine vitamin”, D3 is produced by the skin when we expose it to sunlight. We can also get this vitamin from Paleo food sources such as sardines, salmon, and egg yolks.

Vitamin D3 Receptors are located in the bones, thymus, adrenal glands, kidneys, brain, spinal cord, reproductive organs, pituitary glands, and thyroid gland. Unfortunately, being deficient in this vitamin is the norm and not the exception. According to Thorne Research,

…virtually everyone has a chronic vitamin D deficiency… vitamin D deficiency is the rule rather than the exception in industrialized nations.

This deficiency affects over 1 billion people throughout the world – higher percentages are in modernized countries as we use sunscreen, take showers and typically wear clothes ☺

It is extremely important to have optimal levels of D3. Blood work is necessary to determine the exact level of D3 that an individual needs, but adults need 4,000-10,000 IU per day. The body is capable of producing up to 10,000 IU’s per day if we have full, unprotected sun exposure (hello sunburn). Unfortunately, because we can’t live and work at the beach, most of us will have to look to specific dietary sources (mentioned above) or supplements to bridge the D3 gap.


There are numerous therapeutic benefits to achieving optimal vitamin D3 levels, including lower incidences of the following: type II diabetes, osteoporosis, hypertension, osteoarthritis, depression, metabolic syndrome, multiple sclerosis, epilepsy, migraine headaches, certain autoimmune disorders, inflammatory conditions, polycystic ovary syndrome, asthma, autism, influenza, colds, and cancers of the breast, prostate, and colon! This is one little vitamin that packs a mighty punch! Biotics Research proposes

…adequate exposure to ultraviolet light and/or supplementation with vitamin D3 could save more than 23.000 American lives per year from a reduction in cancer mortality alone.

Convinced yet?

Thankfully, this is one supplement that won’t break the bank. Biotics Research makes a D3 supplement that contains 5,000 IU per capsule and costs around $10 a bottle (contains 100 capsules). As we head into these winter months, it will become extremely important to get adequate levels of D3 from supplements as our sun exposure will become increasingly limited.

Finally, get your D3 levels tested before you start supplementation, take 4-5,000 IU a day and then get tested again after 6-8 weeks. Aim to get your blood levels around 50-60 ng/mL and increase the dosage if you don’t respond to 4-5,000 IU. There is little threat of toxicity at this level as our bodies can make 10,000 IU in less than an hour of sun exposure!

If you want more information, check out Mark’s Daily Apple blog or click here.