Many nutrients are vital to the health of the human body, and vitamin D is no exception. It helps the body absorb calcium, which is essential for ensuring bones grow and stay strong. However, vitamin D deficiency has been linked to a host of other diseases. This list includes depression, heart disease and even some forms of cancer. If you don’t get enough sun, like many swing shift workers, or lack an adequate amount of the nutrient in your diet, you may have a deficiency. Here are ten important signs that you are deficient in this essential nutrient.

Inexplicable Aches and Pains

Lethargy and unexplainable generalized pains are symptoms of some worrisome diseases like fibromyalgia and arthritis. But these symptoms might be telling you that you have a vitamin D deficiency. Without enough vitamin D to absorb adequate amounts of calcium, the bones can lose strength resulting in a deep ache or pain. This may be even more noticeable in the winter when sun exposure decreases for everyone. There are more incidents of broken bones in the winter time. Those with higher levels of vitamin D show increased muscle function in their extremities compared to those with less vitamin D in their blood.

Sweat of the Brow

Especially concerning in infants and young children is an excessively sweaty head, particularly the forehead. This can be a clear indicator of a vitamin D deficiency or a host of other problems. It has been common practice for decades that doctors ask new mothers if they notice any unusual sweating in their infants head, face or neck. This sweating can be indicative of serious problems.There are some-not-so-worrisome causes of a sweaty head, such as fever or being wrapped up for naps. Sweating during feeding is also normal. If you are concerned about your baby’s sweating, contact your pediatrician.

Weakened Immune System

Those with less than sufficient levels of vitamin D are significantly more vulnerable to upper respiratory infections. This includes sinus infections and colds, and lower respiratory infections, like bronchitis and pneumonia. Those with adequate vitamin D levels experienced fewer complications during hospital stays and after surgeries.Vitamin D levels at or above recommended levels are associated with more efficient immune function and decreased respiratory inflammation. With decreased inflammation comes decreased incidence of infection and decreased occurrences of asthma.

Chronic Kidney Disease

Like obesity, chronic kidney problems can be the cause of vitamin D deficiency as opposed to being the result of deficiency. Certain kidney diseases can inhibit the production of vitamin D by the body as well as the breakdown of dietary vitamin D into its useful form. This process is vital to general health because even if adequate amounts of vitamin D are taken in, without the ability to create the active form, the body cannot use the vitamin. This active form of the vitamin helps to feed calcium and other vital minerals to the bones.While there might be vitamin D and calcium available to the body, without proper kidney function, the body cannot use it. As the body starves for vital calcium, it sets off a parathyroid reaction. This is a process that begins dissolving bones for calcium.If you are in the early stages of kidney disease, keep a particular eye on vitamin D levels, especially if dialysis is an option.

Your Skin is Naturally Darker

Whether you are just of a darker complexion or you are an outdoorsy type with a tan, the increased melanin in your system will decrease the amount of vitamin D you produce as a result of direct sunlight. Though it increases your protection from sunburn and hot weather exposure, melanin can make it very difficult to produce the daily recommended vitamin D levels, especially as you age and your need for vitamin D increases.The recommended daily level of vitamin D is 600 IU for all ages, but for those over 70 that number increases to 800 IU, and in African Americans, it can take 10 percent longer to produce the same amount of vitamin D as a fair-skinned person. Sunscreen has the same effect as melanin slowing the process of vitamin D synthesis. This doesn’t mean you can skip sunscreen, but just be aware you may need more exposure to reach the desired amount.

Your Mood is Low

Vitamin D deficiency is directly related to depression. That is because vitamin D plays a huge role in mood regulation. Many of the brain’s major receptors are vitamin D, especially those in the brain linked to mental health. This one fact links mental health to vitamin D deficiency.It is not fully understood why or how the vitamin affects mood but the evidence is mounting. In 2006, a study showed that older adults with less than adequate levels of vitamin D were at an increased risk for depression. There is evidence that adding vitamin D by either dietary or supplemental means can help those who struggle with depression and seasonal affective disorder, which is a more depressed mood during the colder winter months.

Less Than Optimal Muscular Performance

Noticeable muscle weakness, such as trouble climbing stairs or decreased performance in the gym, can be a sign of a vitamin D deficiency. Without enough vitamin D in the diet, muscles don’t get the fuel that they need to function at optimal levels.In young adults and elderly, there have been numerous cases of extended vitamin D deficiency causing extreme muscle weakness, sometimes to a disabling extent. In these cases, the addition of vitamin D into the patient’s diet improved the condition after a short time. This is especially evident in the elderly as their demand for vitamin D increases. If you are experiencing noticeable muscle weakness, adding a suitable supplement might be a good avenue to explore.

Higher Bodyweight

Another inverse relationship, excess weight can make it easier to develop a vitamin D deficiency. As weight increases, the body requires more vitamin D to keep it functioning regularly. This makes it harder for you to hit an appropriate balance.As vitamin D is a fat-soluble nutrient, deficiency precedes obesity as well. As the body notices a lack of fat-soluble nutrients, it is spurred to store more fat. Supplementation and adequate time outside can help combat vitamin D deficiency and all the negative side effects including risk for obesity.

Digestion Difficulties

Vitamin D plays a vital role in so many different bodily functions, from bones to mental well-being, but it is fat soluble. If you have a digestive issue such as Crohn’s disease, irritable bowel syndrome or gallbladder problems, you are less able to absorb this vitamin along with other vital nutrients and may have to take extra steps to ensure that you have the nutrition you need.

Age 50+

As you age, three different things happen in regards to vitamin D. You require more to have the optimal function, you naturally produce less vitamin D when you are outside and exposed to sunlight. And your kidneys have to work harder for longer to turn vitamin D into its most useful form. With this in mind, if you are 50 or older and you are noticing some of the other symptoms on the list, you may want to ask your doctor about vitamin D deficiency and what you can do about it.