Vitamin D helps regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy. A lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain caused by a condition called osteomalacia in adults. It can also increase your risk for fractures.

While the U.S. National Academy of Medicine considers 600–800 IU of daily vitamin D to be sufficient for the majority of the population, the U.S. Endocrine Society recommends 1,500–2,000 IU per day.

Many foods found in the grocery store have vitamin D added – these include dairy products such as milk and yogurt, orange juice and cereal. You can also purchase Vitamin D supplements. But what happens in a SHTF scenario and none of those items were available to you, or you ran through your stockpile of supplements?

Tips for getting vitamin D from the sun

When the sun’s rays hit the skin, processes inside the tissues start making vitamin D.

People do not need to get a tan or burn to get vitamin D from the sun. The body will make all the vitamin D it needs for a day in about half the time it takes the skin to burn.

Many factors affect how much vitamin D a person gets from the sun, such as:

• Time of day. The skin produces more vitamin D when in the sun during the middle of the day, the time it is at its highest point in the sky. When spending prolonged time in the hot sun, wear sunscreen, and stay hydrated.
• Amount of skin exposed. The more skin a person exposes, the more vitamin D the body will make. Exposing the back, for instance, allows the body to produce more vitamin D than just the hands and face.
• Skin color. Pale color skin makes vitamin D more quickly than darker colored skins.

Where a person lives in relation to the equator also has a significant impact on how much vitamin D their bodies can make.

In the United States, people in the sunnier southern states will find it easier to meet their vitamin D needs with sun exposure than those in the northern states. This is especially true in the winter months when the sun is lower in the sky.

Basically people living north of the 37-degree-latitude line — roughly the imaginary line between Philadelphia and San Francisco will have a hard time meeting their vitamin D needs through sunshine alone especially in the winter months.

Frequent, moderate exposure to the sun is healthful, but prolonged exposure can be dangerous and lead to skin cancer.

Six natural sources for Vitamin D