Vitamin D Changed More Than I Expected

I want to share something personal because I think more people, especially women, may be dealing with this and not realizing it.

I exercise.
I ground.
I get outside in the sun every day.
I was already taking 2,000 IU of vitamin D3.

And I was still critically low in vitamin D.

This runs in my family, so genetics may be part of the picture for me. Location may matter too. Depending on where you live, the angle of the sun, season, time spent indoors, skin pigmentation, sunscreen use, age, body composition, and absorption issues can all affect vitamin D status. Even people who are doing “all the right things” can still come up low. Recent reviews and clinical guidance continue to support that vitamin D deficiency remains common worldwide and that risk varies by lifestyle, latitude, skin tone, adiposity, age, and malabsorption-related conditions (Pilz et al., 2023; Bouillon et al., 2022).

What really shocked me was how fast I felt a shift after I started my prescription dose of 50,000 IU vitamin D3. In my case, I felt dramatically better within about 36 hours.

That was my experience. It may not happen that quickly for everyone. But it was dramatic enough that I feel strongly compelled to say this:

People need to get their vitamin D levels checked

If you are exhausted, low, foggy, achy, flat, or just not feeling like yourself, it is worth talking with your healthcare provider and asking whether your vitamin D level should be checked.

Vitamin D deficiency can be associated with bone pain, muscle weakness, fatigue, and impaired musculoskeletal health. It also has broader associations with immune function and overall health, though not every symptom people feel is necessarily caused by vitamin D alone (Bouillon et al., 2022; Pilz et al., 2023). The point is not to self-diagnose everything as vitamin D deficiency. The point is that deficiency can be missed, and it can matter.

Why someone can still be low even with sun and supplements

This is the part I think surprises people.

You can be outdoors regularly and still be low. You can take a standard supplement dose and still be low. Some reasons include:

• living at a latitude or elevation/season combination where UVB exposure is not enough at certain times of year

• spending time outside when UVB is limited, such as early morning or late afternoon

• darker skin pigmentation, which reduces vitamin D production from sunlight

• digestive or absorption issues

• higher body fat levels, which can lower vitamin D bioavailability

• genetics and family patterns

• not taking enough supplementation for your body’s actual needs

Recent literature continues to emphasize that vitamin D requirements and response to supplementation are not identical across people, and that personalized evaluation matters (Pilz et al., 2023; Bouillon et al., 2022).

Other ways to get vitamin D

Sunlight and supplements are not the only options, though they are often the biggest ones.

Food sources

Vitamin D is naturally found in relatively few foods, but some options include:

• fatty fish such as salmon, sardines, trout, and mackerel

• cod liver oil

• egg yolks

• beef liver

Fortified foods

Many people get some vitamin D from fortified foods such as:

• milk

• some plant milks

• yogurt

• breakfast cereals

• orange juice

Prescription replacement

For people who are significantly deficient, healthcare providers sometimes prescribe high-dose vitamin D, such as weekly dosing for a set period, followed by a maintenance plan. Clinical guidance supports using higher replacement doses for deficiency under medical supervision rather than guessing and taking large doses on your own (Endocrine Society, 2024 clinical guidance update; Pilz et al., 2023).

A loving caution: more is not always better

Vitamin D is important, but megadosing without guidance is not a good idea. Too much vitamin D can cause harm, including hypercalcemia and related complications. That is why testing and working with a healthcare provider matters.

This is not about fear. It is about accuracy.

What I want women especially to hear

If you are doing a lot “right” and still feel depleted, do not assume it is all in your head.

It may be stress.
It may be hormones.
It may be sleep.
It may be iron, thyroid, or something else.
And yes, it may also be vitamin D.

For me, getting proper treatment for deficiency made a profound difference very quickly. I am sharing this because I think some women are walking around feeling awful and blaming themselves when they may actually need lab work and real medical support.

You deserve to feel better than “barely functioning.”

If this resonates with you, consider asking your healthcare provider about testing your vitamin D level and what range they want to see for your health picture.

References

Bouillon R, Marcocci C, Carmeliet G, et al. Skeletal and extraskeletal actions of vitamin D: current evidence and outstanding questions. Endocrine Reviews. 2022.

Pilz S, Trummer C, Theiler-Schwetz V, et al. Vitamin D: current guidelines and future outlook. Frontiers in Endocrinology. 2023.

Endocrine Society. Clinical guideline/update on vitamin D for disease prevention and deficiency management. 2024.

U.S. National Institutes of Health, Office of Dietary Supplements. Vitamin D Fact Sheet for Health Professionals. Updated 2022–2024.