A Guide to Vitamin D

vitamin D

A Guide to Vitamin D

You’ve probably noticed milk, orange juice, or cereal fortified with vitamin D. But what is vitamin D, why do we need it, and how exactly do we get it?

Advantages of Vitamin D

Vitamin D benefits the body in several ways. Most notably, as a nutrient used by our bodies to aid in calcium absorption, it improves the strength and health of your teeth and bones. Vitamin D also improves and strengthens mental development and functioning. Regular intake of this nutrient can aid in creating a healthy, agile, and well-functioning mind even as you grow old. Vitamin D is also known to act as a natural booster to your autoimmune system.

Vitamin D Deficiency

As per the National Institutes of Health, the recommended vitamin D daily allowance for adults is 600 IU/day, with the upper-level intake at 4,000 IU/day. 

Causes of Deficiency

Vitamin D deficiency has been linked to several medical conditions and lifestyle situations. Factors such as advanced age, lack of mobility, obesity, dark skin color, and being exclusively breastfed increase the likelihood of vitamin D deficiency. Additionally, kidney disease, liver disease, obesity, celiac disease, cystic fibrosis, and Crohn’s disease can contribute to vitamin D deficiency.

Certain medications can also decrease levels of vitamin D in the body. Inform your doctor of any drugs and supplements you take.

Results of Deficiency

Vitamin D deficiency is very common among children. Moreover, deficiency at a younger age results in more susceptibility to ailments in bones and joints at an advanced age. Vitamin D deficiency can cause rickets in children and osteoporosis and even arthritis in the elderly. Vitamin D deficiencies can also result in degenerative diseases at an advanced age.

Sources of Vitamin D

There are three main sources of vitamin D: sunlight, supplements, and food.


Sunshine is an excellent free source of vitamin D. Your skin produces vitamin D as it is exposed to sunlight. Several factors affect the amount of vitamin D that is produced, including the length of exposure, season, time of day, air quality, and cloudiness. Be cautious of excessive sun exposure, however, as the risk of skin cancer increases.


Vitamin D supplements are an option if vitamin D levels test low or if sources from diet and sunlight are inadequate. Your doctor can help guide you in determining if a vitamin D supplement is right for you and the proper dosage. Work with your doctor to choose a high-quality supplement. Make sure to alert your doctor to any medications and additional supplements you may be taking.


While eating a diet full of vitamin D–rich foods can provide some level of vitamin D, it would be difficult to get the amount of vitamin D your body needs through diet alone. Fish like salmon, tuna, and swordfish are good sources of vitamin D. Foods fortified with vitamin D, such as milk, yogurt, and orange juice, are also an excellent choice.

Whether through sunlight, supplements, or vitamin D–rich foods, it’s important to ensure you are getting adequate levels of vitamin D. It’s essential for bone strength, mental health, and immunity throughout life.

As a provider of BioTE Nutraceuticals, Dr. Sue Reddy understands what is required to live a healthy, active life and can assist you in achieving optimal nutritional health. Give Dr. Reddy a call today. Her staff would be more than happy to set up an appointment and answer any questions you may have.