According to the Harvard School of Public Health, a staggering 1 billion people worldwide are vitamin D deficient. How do you know if you’re one of them?

Signs and symptoms of a vitamin D deficiency include:

  • Unexpected muscle weakness
  • Stress fractures
  • Fatigue
  • Depression
  • Pain sensitivity or chronic pain
  • High blood pressure

If left unchecked, low levels of vitamin D could also lead to increased risks of multiple sclerosis, osteoporosis, pneumonia, heart problems, Parkinson’s disease, and even dementia.

There Goes The Sun

While sunlight is reputed as the greatest natural source of vitamin D, sunlight is actually what allows our bodies to produce it. In areas like the U.K. or the Northeastern U.S., which typically see a shortage of ultraviolet B (UVB) rays, you’re likely to find a higher incidence of vitamin D deficiency.

During the warmer months, try to get at least 15 minutes of noonday sun, in shorts and a sleeveless top, without any sunscreen. Depending on your skin type, you could need more or less time. Those with higher levels of melanin in their skin take longer to produce vitamin D and may require more sun exposure.

There is also the option of UVB tanning beds, but very close monitoring is strongly advised. Doctors have repeatedly warned of developing melanoma, the deadliest form of skin cancer, from tanning bed overuse.

Edible Sources of Vitamin D

Sunlight may not be for everyone, so incorporating vitamin-D rich foods into your diet always helps. Dairy products still have the highest vitamin-D content of all the available food sources. But for the lactose intolerant among us, options include:

  • Mushrooms (portobello, shiitake, oyster, button)
  • Orange juice
  • Eggs (particularly the yolk)
  • Cereal and oatmeal
  • Oily fish, such as salmon, trout, tuna, or sardines

For the more adventurous foodies, caviar is another great source. There are also breads and lactose-free soy, rice, and almond-based beverages fortified with vitamin D.

As Easy As D-2-3

If you’ve ever looked at vitamin D supplements at a pharmacy, you might have wondered what’s so special about vitamin D3.

Vitamin D3 (cholecalciferol) is primarily derived from the fat of lambs’ wool and is the easiest to absorb into the bloodstream. Vitamin D2 (ergocalciferol) is entirely plant-based, but it cannot be naturally synthesized by the body like D3 can. Vitamin D2 was used primarily to treat rickets and parahypothyroid, but the medical consensus has been for some time that they are equally effective.

A doctor once recommended a vitamin D3 supplement to your humble narrator. He suggested an intake of roughly 8,000 international units (IU) per day to boost my numbers, and to then scale back to 1000 - 2000 IU per day once the levels were acceptable. I immediately noticed increased and more consistent energy levels, less fatigue, and better overall health with vitamin D supplements.

It’s worth noting that there is such a thing as taking too much vitamin D, which may cause calcium to build up in your blood, manifesting as poor appetite, vomiting, kidney problems, and other adverse symptoms.

If your blood calcium levels are already high, consult with your doctor about the best course of action to maintain healthy amounts of vitamin D in your system.